diff --git a/graphs_trees/bst/__init__.py b/graphs_trees/bst/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/graphs_trees/bst/bst.py b/graphs_trees/bst/bst.py
new file mode 100644
index 0000000..3b17225
--- /dev/null
+++ b/graphs_trees/bst/bst.py
@@ -0,0 +1,53 @@
+from collections import deque
+
+
+class Node(object):
+
+    def __init__(self, data):
+        self.data = data
+        self.left = None
+        self.right = None
+
+    def insert(self, data):
+        if data <= self.data:
+            if self.left is None:
+                self.left = Node(data)
+            else:
+                self.left.insert(data)
+        else:
+            if self.right is None:
+                self.right = Node(data)
+            else:
+                self.right.insert(data)
+
+    def in_order_traversal(self, visit_func):
+        if self.left is not None:
+            self.left.in_order_traversal(visit_func)
+        visit_func(self.data)
+        if self.right is not None:
+            self.right.in_order_traversal(visit_func)
+
+    def pre_order_traversal(self, visit_func):
+        visit_func(self.data)
+        if self.left is not None:
+            self.left.pre_order_traversal(visit_func)
+        if self.right is not None:
+            self.right.pre_order_traversal(visit_func)
+
+    def post_order_traversal(self, visit_func):
+        if self.left is not None:
+            self.left.post_order_traversal(visit_func)
+        if self.right is not None:
+            self.right.post_order_traversal(visit_func)
+        visit_func(self.data)
+
+    def bfs(self, visit_func):
+        queue = deque()
+        queue.append(self)
+        while len(queue) > 0:
+            node = queue.popleft()
+            visit_func(node.data)
+            if node.left is not None:
+                queue.append(node.left)
+            if node.right is not None:
+                queue.append(node.right)
\ No newline at end of file
diff --git a/graphs_trees/bst/bst_challenge.ipynb b/graphs_trees/bst/bst_challenge.ipynb
new file mode 100644
index 0000000..2dc27d7
--- /dev/null
+++ b/graphs_trees/bst/bst_challenge.ipynb
@@ -0,0 +1,211 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "<small><i>This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges).</i></small>"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Challenge Notebook"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Problem: Implement a binary search tree with an insert method.\n",
+    "\n",
+    "* [Constraints](#Constraints)\n",
+    "* [Test Cases](#Test-Cases)\n",
+    "* [Algorithm](#Algorithm)\n",
+    "* [Code](#Code)\n",
+    "* [Unit Test](#Unit-Test)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Constraints\n",
+    "\n",
+    "* Can we assume we are working with valid integers?\n",
+    "    * Yes\n",
+    "* Can we assume all left descendents <= n < all right descendents?\n",
+    "    * Yes\n",
+    "* For simplicity, can we use just a Node class without a wrapper Tree class?\n",
+    "    * Yes"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Test Cases\n",
+    "\n",
+    "### Insert\n",
+    "\n",
+    "Insert will be tested through the following traversal:\n",
+    "\n",
+    "### In-Order Traversal (Provided)\n",
+    "\n",
+    "* 5, 2, 8, 1, 3 -> 1, 2, 3, 5, 8\n",
+    "* 1, 2, 3, 4, 5 -> 1, 2, 3, 4, 5"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Algorithm\n",
+    "\n",
+    "Refer to the [solution notebook](https://github.com/donnemartin/interactive-coding-challenges/graphs_trees/bst/bst_solution.ipynb).  If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Code"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Note: `in_order_traversal` is provided for testing purposes."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "class Node(object):\n",
+    "\n",
+    "    def __init__(self, data):\n",
+    "        # TODO: Implement me\n",
+    "\n",
+    "    def insert(self, data):\n",
+    "        # TODO: Implement me\n",
+    "\n",
+    "    def in_order_traversal(self, visit_func):\n",
+    "        if self.left is not None:\n",
+    "            self.left.in_order_traversal(visit_func)\n",
+    "        visit_func(self.data)\n",
+    "        if self.right is not None:\n",
+    "            self.right.in_order_traversal(visit_func)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Unit Test"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "**The following unit test is expected to fail until you solve the challenge.**"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": [
+    "%run ../utils/captured_output.py"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "# %load test_bst.py\n",
+    "from __future__ import print_function\n",
+    "from nose.tools import assert_equal\n",
+    "\n",
+    "\n",
+    "class TestTree(object):\n",
+    "\n",
+    "    def test_tree(self):\n",
+    "        root = Node(5)\n",
+    "        root.insert(2)\n",
+    "        root.insert(8)\n",
+    "        root.insert(1)\n",
+    "        root.insert(3)\n",
+    "\n",
+    "        with captured_output() as (out, err):\n",
+    "            root.in_order_traversal(sys.stdout.write)\n",
+    "            assert_equal(out.getvalue().strip(), '12358')\n",
+    "\n",
+    "        root = Node(1)\n",
+    "        root.insert(2)\n",
+    "        root.insert(3)\n",
+    "        root.insert(4)\n",
+    "        root.insert(5)\n",
+    "\n",
+    "        with captured_output() as (out, err):\n",
+    "            root.in_order_traversal(sys.stdout.write)\n",
+    "            assert_equal(out.getvalue().strip(), '12345')\n",
+    "\n",
+    "        print('Success: test_tree')\n",
+    "\n",
+    "\n",
+    "def main():\n",
+    "    test = TestTree()\n",
+    "    test.test_tree()\n",
+    "\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    main()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Solution Notebook\n",
+    "\n",
+    "Review the [solution notebook](https://github.com/donnemartin/interactive-coding-challenges/graphs_trees/bst/bst_solution.ipynb) for a discussion on algorithms and code solutions."
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.10"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/graphs_trees/bst/bst_solution.ipynb b/graphs_trees/bst/bst_solution.ipynb
new file mode 100644
index 0000000..8d3862b
--- /dev/null
+++ b/graphs_trees/bst/bst_solution.ipynb
@@ -0,0 +1,238 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "<small><i>This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges).</i></small>"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Solution Notebook"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Problem: Implement a binary search tree with an insert method.\n",
+    "\n",
+    "* [Constraints](#Constraints)\n",
+    "* [Test Cases](#Test-Cases)\n",
+    "* [Algorithm](#Algorithm)\n",
+    "* [Code](#Code)\n",
+    "* [Unit Test](#Unit-Test)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Constraints\n",
+    "\n",
+    "* Can we assume we are working with valid integers?\n",
+    "    * Yes\n",
+    "* Can we assume all left descendents <= n < all right descendents?\n",
+    "    * Yes\n",
+    "* For simplicity, can we use just a Node class without a wrapper Tree class?\n",
+    "    * Yes"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Test Cases\n",
+    "\n",
+    "### Insert\n",
+    "\n",
+    "Insert will be tested through the following traversal:\n",
+    "\n",
+    "### In-Order Traversal (Provided)\n",
+    "\n",
+    "* 5, 2, 8, 1, 3 -> 1, 2, 3, 5, 8\n",
+    "* 1, 2, 3, 4, 5 -> 1, 2, 3, 4, 5"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Algorithm\n",
+    "\n",
+    "### Insert\n",
+    "\n",
+    "* If the data is <= the current node's data\n",
+    "    * If the current node's left child is None, set it to Node(data)\n",
+    "    * Else, recursively call insert on the left child\n",
+    "* Else\n",
+    "    * If the current node's right child is None, set it to Node(data)\n",
+    "    * Else, recursively call insert on the right child\n",
+    "\n",
+    "Complexity:\n",
+    "\n",
+    "* Time: O(log n)\n",
+    "* Space: O(1)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Code"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "class Node(object):\n",
+    "\n",
+    "    def __init__(self, data):\n",
+    "        self.data = data\n",
+    "        self.left = None\n",
+    "        self.right = None\n",
+    "\n",
+    "    def insert(self, data):\n",
+    "        if data <= self.data:\n",
+    "            if self.left is None:\n",
+    "                self.left = Node(data)\n",
+    "            else:\n",
+    "                self.left.insert(data)\n",
+    "        else:\n",
+    "            if self.right is None:\n",
+    "                self.right = Node(data)\n",
+    "            else:\n",
+    "                self.right.insert(data)\n",
+    "\n",
+    "    def in_order_traversal(self, visit_func):\n",
+    "        if self.left is not None:\n",
+    "            self.left.in_order_traversal(visit_func)\n",
+    "        visit_func(self.data)\n",
+    "        if self.right is not None:\n",
+    "            self.right.in_order_traversal(visit_func)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Unit Test"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "%run ../utils/captured_output.py"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Overwriting test_bst.py\n"
+     ]
+    }
+   ],
+   "source": [
+    "%%writefile test_bst.py\n",
+    "from __future__ import print_function\n",
+    "from nose.tools import assert_equal\n",
+    "\n",
+    "\n",
+    "class TestTree(object):\n",
+    "\n",
+    "    def test_tree(self):\n",
+    "        root = Node(5)\n",
+    "        root.insert(2)\n",
+    "        root.insert(8)\n",
+    "        root.insert(1)\n",
+    "        root.insert(3)\n",
+    "\n",
+    "        with captured_output() as (out, err):\n",
+    "            root.in_order_traversal(sys.stdout.write)\n",
+    "            assert_equal(out.getvalue().strip(), '12358')\n",
+    "\n",
+    "        root = Node(1)\n",
+    "        root.insert(2)\n",
+    "        root.insert(3)\n",
+    "        root.insert(4)\n",
+    "        root.insert(5)\n",
+    "\n",
+    "        with captured_output() as (out, err):\n",
+    "            root.in_order_traversal(sys.stdout.write)\n",
+    "            assert_equal(out.getvalue().strip(), '12345')\n",
+    "\n",
+    "        print('Success: test_tree')\n",
+    "\n",
+    "\n",
+    "def main():\n",
+    "    test = TestTree()\n",
+    "    test.test_tree()\n",
+    "\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    main()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Success: test_tree\n"
+     ]
+    }
+   ],
+   "source": [
+    "%run -i test_bst.py"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.10"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/graphs_trees/bst/test_bst.py b/graphs_trees/bst/test_bst.py
new file mode 100644
index 0000000..894fc9e
--- /dev/null
+++ b/graphs_trees/bst/test_bst.py
@@ -0,0 +1,37 @@
+from __future__ import print_function
+from nose.tools import assert_equal
+
+
+class TestTree(object):
+
+    def test_tree(self):
+        root = Node(5)
+        root.insert(2)
+        root.insert(8)
+        root.insert(1)
+        root.insert(3)
+
+        with captured_output() as (out, err):
+            root.in_order_traversal(sys.stdout.write)
+            assert_equal(out.getvalue().strip(), '12358')
+
+        root = Node(1)
+        root.insert(2)
+        root.insert(3)
+        root.insert(4)
+        root.insert(5)
+
+        with captured_output() as (out, err):
+            root.in_order_traversal(sys.stdout.write)
+            assert_equal(out.getvalue().strip(), '12345')
+
+        print('Success: test_tree')
+
+
+def main():
+    test = TestTree()
+    test.test_tree()
+
+
+if __name__ == '__main__':
+    main()
\ No newline at end of file