Since it will be some time until data will be available comparing clomipramine and fluoxetine for the treatment of patients with obsessive-compulsive disorder (OCD), a meta-analysis of previous studies was performed in an attempt to gain some information about comparable efficacy and side effects of these two commonly used agents. In 31 OCD patients receiving clomipramine in a controlled trial and 72 OCD patients receiving fluoxetine openly, both drugs appeared effective, with clomipramine having a somewhat larger effect than fluoxetine. Different side effect profiles may have a bearing on patient selection.