Obsessive-Compulsive Disorder (OCD) was considered a rare disorder prior to 1984 when the initial results from the Epidemiologic Catchment Area survey demonstrated a substantial prevalence of the disorder (1). Thus there may be many patients today who entered treatment prior to 1984 with undiagnosed OCD. This paper gives the history of one such patient and reviews the current literature on OCD as it pertains to the diagnostic evidence in this case