Psychiatric morbidity in an Indian general practice was studied using the 12 item version of the General Health Questionnaire to screen 882 patients who represented 9000 consecutive adult patients attending the practice. The questionnaire was valid with a cutting score of 1/2 when compared with section 1 of the standardised Indian Psychiatric Survey Schedule. The probable prevalence of psychiatric morbidity was 35.9%. The general practitioner identified only about 25% of patients. Five of the 12 questions on the General Health Questionnaire had a higher discriminatory capacity, and the performance of the patients on these five questions was valid when compared to section 1 of the Indian Psychiatric Survey Schedule.