The present study investigated whether social support and family members' reactions to clients with obsessive compulsive disorder played a significant role in the follow-up outcome of an intensive behavioral treatment program. The roles OCD symptoms, moodstate, social functioning and life events were also assessed. General social support did not predict relapse, but significant others' empathy and positive interactions were associated with maintenance of gains. Negative family interactions (especially criticism and anger) and belief that clients could control their symptoms predicted relapse. Higher levels of post-treatment anxiety and depression and poorer functioning were related to negative outcome, as was distress from life events during follow-up. Results are discussed with respect to possible mechanisms of action and future research needs.