We reviewed the extant literature to evaluate the current evidence regarding the efficacy and safety of anticonvulsants in the treatment of obsessive–compulsive and related disorders. Relevant literature was accessed using the Cochrane database, embase and PubMed on 29 October 2013. Prospective studies examining the efficacy of anticonvulsants in obsessive–compulsive and related disorders were included. Case reports, case series, and retrospective studies were excluded. A total of 10 studies were included in this review. The studies of obsessive–compulsive disorder, except for two negative studies, showed favorable efficacy results of anticonvulsants. In one study on body dysmorphic disorder, levetiracetam showed favorable efficacy. In two lamotrigine studies for pathologic skin-picking, the efficacy findings were inconsistent. In one trichotillomania study, topiramate had reduced hair-pulling symptoms. Despite limited evidence, our review suggests that anticonvulsants have a potential role in the treatment of obsessive–compulsive and related disorders.