The purpose of this review was to assess the validity of proposed obsessive-compulsive disorder (OCD) subtypes by utilizing Robins and Guze's (1970) five guidelines for developing subtypes: (1) clinical description, (2) follow-up studies, (3) laboratory studies, (4) delimitation from other disorders, and (5) family studies, and an additional (6) treatment response guideline. Accordingly, a review of the literature was conducted focusing on these guidelines. The resulting studies showed that, when utilizing these criteria, there is no operationally valid OCD subtype. Although most proposed subtypes had sufficient research conducted on them, none of them met all six of the guidelines. Although seven proposed subtypes met all of the guidelines that had been examined within them, additional research is required to assess whether they constitute valid subtypes.