The need for evidence-based mental health treatments i.e., 'treatment based on the best available science or research evidence‟1, has been stressed from scientific, ethical, and marketing perspectives. While empirical evidence supports both the efficacy and effectiveness of cognitive behavior therapy (CBT) for Obsessive-Compulsive Disorder (OCD), demand for clinicians trained in these approaches far exceeds supply. New technologies provide the opportunity to facilitate access to this specialized treatment. A growing body of research has found that web-based self-administered psychotherapy is highly effective, cost-efficient, and can achieve clinical improvements similar to those obtained with clinician administered therapy. The long-term goal of this project is to improve clinical and occupational functioning and decrease disability associated with OCD by improving access to effective treatments through the use of web-based CBT treatment. The intervention involves a computer program (BT STEPS) and human interaction via telephone. The inclusion of human interaction for coaching and encouragement has been found to significantly increase compliance and success rates in computerized self-help. Whether treatment outcomes differ when this coaching is done by a therapist versus when done by a trained non-therapist has not been studied. This is the first program to examine a hybrid model involving different levels of remote clinician coaching in combination with an on-line self-help tutorial. In Phase I the investigators will test the efficacy and feasibility of computer therapy alone (n=35), computer plus nontherapist coach (n=35) and computer plus CBT therapist coach. In phase II the investigators will do a fully powered study comparing our model to traditional face-to-face therapy.