This study deals with clinical features of obsessive-compulsive disorder in 100 patients who were referred to selected clinics in Tehran. Using Yale Brown Obsessive-Compulsive Check-list, Millon Clinical Multiaxial Inventory, Beck Depression Inventory and a demographic questionaire, this study represents frequency of different signs and symptoms of o CD, rate of depression, personality disorders comorbidity and demographic characteristics of the sample. The findings show that phenomenological characteristics of OCD in these patients are generally congruent with findings of similar researches in other countries. The exeptions are that the content of symptoms is culture bond, rate of hospitalization is very low and rate of non-pharmacologic treatment is also low. According to these findings, guidelines for designing measurment tools and treatment strategies have been suggested.