diff --git a/01_binary_search_trees/bst.py b/01_binary_search_trees/bst.py
index 6a53a30..f5e88da 100644
--- a/01_binary_search_trees/bst.py
+++ b/01_binary_search_trees/bst.py
@@ -4,6 +4,7 @@ Binary Search Tree Implementation
 2013/07
 """
 
+
 class BinarySearchTree():
     """
     Defines a complete binary search Tree.
@@ -24,17 +25,17 @@ class BinarySearchTree():
         the node.
         """
         if self.size == 0:
-            self.root_node = BinarySearchNode(value, None) # root node has no parent
+            self.root_node = BinarySearchNode(value, None)  # root node has no parent
 
         else:
             node = self.root_node
             is_left = None
-            while(node != None):
-                ptr_node = node # keep parent in memory
+            while(node is not None):
+                ptr_node = node  # keep parent in memory
                 if node.value > value:  # we go to the left child
                     node = node.left_child
                     is_left = True
-                else: # we move to the right child. This means = case too
+                else:  # we move to the right child. This means = case too
                     node = node.right_child
                     is_left = False
 
@@ -52,10 +53,9 @@ class BinarySearchTree():
         Returns the highest node value of the tree.
         Otherwise, returns None
         """
-
         if self.size == 0:
             return None
-        else:  # we have values in the node
+        else:  # we have nodes in the tree
             node = self.root_node
             while(node.has_right_child()):
                 node = node.right_child
@@ -63,6 +63,22 @@ class BinarySearchTree():
             # we have the leaf
             return node.value
 
+    def min(self):
+        """
+        Returns the lowest node value of the tree.
+        Otherwise returns None
+        """
+        if self.size == 0:
+            return None
+        else:  # we have nodes in the tree
+            node = self.root_node
+            while(node.has_left_child()):
+                node = node.left_child
+
+            # we have the leaf
+            return node.value
+
+
 class BinarySearchNode():
     """
     Defines any node of the Binary Search Tree.
@@ -81,4 +97,3 @@ class BinarySearchNode():
 
     def has_right_child(self):
         return self.right_child is not None
-
diff --git a/01_binary_search_trees/bst_test.py b/01_binary_search_trees/bst_test.py
index 052b52f..a56844d 100644
--- a/01_binary_search_trees/bst_test.py
+++ b/01_binary_search_trees/bst_test.py
@@ -21,11 +21,11 @@ class test_binary_search_tree(unittest.TestCase):
 
         self.assertEqual(bst.size, 1)
 
-        node_val2= 4
+        node_val2 = 4
         bst.add(node_val2)
-        node_val3= 10
+        node_val3 = 10
         bst.add(node_val3)
-        node_val4= 16
+        node_val4 = 16
         bst.add(node_val4)
         self.assertEqual(bst.size, 4)
 
@@ -40,11 +40,11 @@ class test_binary_search_tree(unittest.TestCase):
         bst = BinarySearchTree()
         node_val1 = 6
         bst.add(node_val1)
-        node_val2= 4
+        node_val2 = 4
         bst.add(node_val2)
-        node_val3= 10
+        node_val3 = 10
         bst.add(node_val3)
-        node_val4= 16
+        node_val4 = 16
         bst.add(node_val4)
         self.assertEqual(bst.size, 4)
 
@@ -55,11 +55,10 @@ class test_binary_search_tree(unittest.TestCase):
         self.assertTrue(node.has_right_child())
         self.assertEqual(node.right_child.value, node_val3)
 
-        node = node.left_child # we have 4 now
+        node = node.left_child  # we have 4 now
         self.assertFalse(node.has_left_child())
         self.assertFalse(node.has_right_child())
 
-
     def test_max(self):
 
         #    6
@@ -74,15 +73,39 @@ class test_binary_search_tree(unittest.TestCase):
 
         node_val1 = 6
         bst.add(node_val1)
-        node_val2= 4
+        node_val2 = 4
         bst.add(node_val2)
-        node_val3= 10
+        node_val3 = 10
         bst.add(node_val3)
-        node_val4= 16
+        node_val4 = 16
         bst.add(node_val4)
         self.assertEqual(bst.size, 4)
 
         self.assertEqual(bst.max(), node_val4)
 
+    def test_min(self):
+
+        #    6
+        #   / \
+        #  4   10
+        #       \
+        #        16
+
+        bst = BinarySearchTree()
+
+        self.assertEqual(bst.min(), None)
+
+        node_val1 = 6
+        bst.add(node_val1)
+        node_val2 = 4
+        bst.add(node_val2)
+        node_val3 = 10
+        bst.add(node_val3)
+        node_val4 = 16
+        bst.add(node_val4)
+        self.assertEqual(bst.size, 4)
+
+        self.assertEqual(bst.min(), node_val2)
+
 if __name__ == '__main__':
-    unittest.main()
\ No newline at end of file
+    unittest.main()