Searching in a binary search tree for a specific key can be programmed [[recursion (computer science)|recursively]] or [[iteration#Computing|iteratively]].
Searching begins by examining the [[tree (data structure)#root nodes|root node]]. If the tree is [[Null pointer|{{math|{{text|nil}}}}]], the key being searched for does not exist in the tree. Otherwise, if the key equals that of the root, the search is successful and the node is returned. If the key is less than that of the root, the search proceeds by examining the left subtree. Similarly, if the key is greater than that of the root, the search proceeds by examining the right subtree. This process is repeated until the key is found or the remaining subtree is <math>\text{nil}</math>. If the searched key is not found after a <math>\text{nil}</math> subtree is reached, then the key is not present in the tree.{{r|algo_cormen|pp=290-291}}
