This paper describes a cross-sectional case control study to measure the prevalence of psychological morbidity in first year medical students and compare it to the prevalence in in a randomly selected control group of other first year students at Edinburgh University. The study was conducted anonymously using the 60 item General Health Questionnaire. Participation rates were over 90% in both subjects and controls. A total of 17% of medical students had symptoms of psychological morbidity which may benefit from treatment and a further 29% of medical students had symptoms of psychological distress which would be expected to remit spontaneously. A similar rate was found in the control group of students. This suggests that if medical students or doctors, later in their careers, fare badly in terms of mental health then this may well be related to aspects of their lives and is not an intrinsic characteristic.