PURPOSE: To investigate stress in medical students, law students, and graduate students at McGill University using a well-validated measure, the Derogatis Stress Profile (DSP). METHOD: The DSP was administered to the medical students in November and December 1994. For comparison, the DSP was also administered to the undergraduate law students and the graduate students. In November 1995 the DSP was administered to the first- and second-year medical students. Results were analyzed with a number of statistical methods. RESULTS: The response rates for the medical students, the law students, and the graduate students in 1994-95 were 70%, 96%, and 43%, respectively. The response rate for the first- and second-year medical students in 1995-96 was 57%. The medical students had subjective feelings of stress that are marginally above population norms, but their total-stress scores (related to environmental factors, personality mediators, and emotional responses) were below those of the general population, the law students, and the graduate students. Elevated depression scores in a minority of the students did not seem to be related directly to the stresses associated with medical school. The transition from basic science training to clinical training was associated with an increase in stress and depressed mood. CONCLUSION: Medical students are not greatly stressed relative to other groups, hence other explanations must be sought for the elevated levels of depression in some students. One situation in which stress appears to be particularly important is in the transition from basic science training to clinical training. Targeted interventions may be an effective way of dealing with this problem.