Cognitive-behavioral therapy (CBT) for obsessive-compulsive disorder (OCD) has been shown to be a highly effective treatment for children and adults. In the current review, we briefly describe the historical developments of the treatment, and recent findings related to five areas of inquiry: 1) Does intensity of CBT impact outcome? 2) Does CBT work better on some subtypes of OCD than others? 3) How do cognitive and behavior strategies relate to outcome? 4) How well does CBT work for children and adolescents with OCD? and 5) Does the combination of CBT and medication work better than CBT alone? After a discussion of these questions, we mention some areas currently being examined.