Background: It has been suggested that the perinatal period is a period of increased risk for the development and/or exacerbation of OCD and that postpartum OCD (ppOCD) presents a distinct clinical picture. This raises the possibility that ppOCD might be a distinct subtype of OCD. This review examines this contention. Method: A search using Ovid (Medline, PsycINFO and Embase), EBSCO, Cochrane Library, Web of Science (ISI), Pubmed databases and Google Scholar was carried out using the key words: “obsessive compulsive disorder” (and derivatives), “perinatal”, “pregnancy”, “postnatal”, “postpartum”, “mothers” (and derivatives), “anxiety disorders” and “subtypes.” These articles and their references were reviewed. Results: The majority of studies reviewed were retrospective, which makes it impossible to infer causality. Two prospective studies found a higher incidence of OCD in the postpartum period. These were carried out in Turkey and Brazil and, as such, may be limited in their applicability to other cultural groups. Conclusion: The concept of ppOCD as a specific subtype has not been robustly demonstrated. The evidence that OCD is more prevalent in the postpartum period is mixed. The evidence that OCD in the postpartum period presents a distinctive clinical picture with specific symptomatology and course is more compelling. In view of the impact of culture and religion on the expression of OCD, collaborative, international, prospective studies that take into account the methodological and definitional issues raised in this review are necessary to provide clarification.