Data on the epidemiology of psychiatric disorders from different parts of the world using similar methods and diagnostic criteria have previously not been available. This article presents data on lifetime and annual prevalence rates, age at onset, symptom profiles, and comorbidity of obsessive compulsive disorder (OCD), using DSM-III criteria, from community surveys in seven countries: the United States, Canada, Puerto Rico, Germany, Taiwan, Korea, and New Zealand. The OCD annual prevalence rates are remarkably consistent among these countries, ranging from 1.1/100 in Korea and New Zealand to 1.8/100 in Puerto Rico. The only exception is Taiwan (0.4/100), which has the lowest prevalence rates for all psychiatric disorders. The data for age at onset and comorbidity with major depression and the other anxiety disorders are also consistent among countries, but the predominance of obsessions or compulsions varies. These findings suggest the robustness of OCD as a disorder in diverse parts of the world.