This study used a large, obsessive- compulsive disorder (OCD) population (N = 157) without comorbidity, and compared them to the general population of the States of New York on the following demographic variables: sex ratio, age of onset, age first seen, marital status, occupation, birth trauma, substance abuse, religion, past psychiatric treatment, and parents' psychiatric history. A 1: 1 sex ratio with a significant gender difference was found for age of onset (females = 20.8; males = 16.3 years), and for age first seen (females = 26.4; males 20.3 years). Other significant findings were the following: More single male OCD patients, fewer widowed female patients, more white-collar workers, less drug abusers, more alcohol abstainers, and less non-problem drinkers as compared to the general population. Significantly also, more atheist/agnostic OCD patients were found as compared to other patients. For the first time, the findings can be evaluated against a comparative group.