We present the results of a systematic review on the effectiveness of pharmacological treatments for children and adolescents with obsessive-compulsive disorder. Sixty-four studies fulfilled the selection criteria, being the most of them focused in SSRI and Clomipramine. The trials on augmentation strategies and third line monotherapies are scarce, being the majority open-trials and case series. Similarly, studies on combined treatment (psychological and pharmacological) are few; furthermore this is a relevant future research line. It is also remarkable the lack of quasi-experimental and experimental comparison studies and the long-term follow-up measures.