The authors describe the problem of impairment of medical students from the point of view of mental health professionals who have directed a large and successful evaluation and referral service for students suffering from a wide array of stress-related and mental disorders. They outline the nature of the impairment problems, the history of the efforts at their medical school to address these problems, and their recent experience in providing mental health services to students who are referred for evaluation and treatment. Diagnostic data, referral and the implications of mental disorders for medical students are discussed. The authors offer some suggestions for the formation of student well-being committees prior to the implementation of student assistance programmes to address the problems of substance abuse.