There is increasing evidence that obsessive-compulsive disorder (OCD) is mediated by genetic factors. Although the precise mechanism of inheritance is unclear, recent evidence has pointed towards the involvement of the serotonergic and dopaminergic systems in the disorder's development. Objectives: To examine the clinical profile of symptoms in obsessive compulsive patients and their first and second degree relatives. Subjects and Methods: This study was designed in the Institute of psychiatry, Ain Shams University Hospitals. After signing an informed consent form, all the subjects 23 patients and 19 relatives were diagnosed according to DSM-IV and Structured Clinical Interview for DSM-IV (SCID I) and General Health Questionaire for psychiatric morbidity. Severity of OCD symptoms was assessed using Yale-Brown Obsessive Compulsive Scale (Y-BOCS) Symptom analysis was done on four symptom factor levels and presenting symptoms. Results: Showed 15 OCD patients had positive family history of psychiatric illness. 19 of their relatives showed 11 had OCD, 6 had psychosis and 3 had depression. The most prevalent symptom in OCD patients and their relatives was washing compulsions and religious obsessions. Conclusion: Genetic factors account for most of OCD symptoms in patients diagnosed with the disorder. Environmental factors also play a role in how these symptoms are expressed by observational learning.