The development of a questionnaire to assess the attitudes of medical students towards old people is described. Principal components analysis of the responses of 114 first-year medical students revealed two orthogonal factors, named negative attitudes and medical intervention. Scores on these factors were compared among three groups of medical students: first-year students, 64 clinical phase medical students prior to a geriatric medicine course, and 69 medical students who had completed a geriatric medicine course. Negative attitudes scores did not differ between first year and the clinical years, but were reduced after the geriatric medicine course. Scores on the medical intervention factor reduced significantly from first year to the clinical years and were not reduced further by the geriatric medicine course. Women tended to have lower scores on negative attitudes. Medical students appeared to change their attitudes concerning the degree to which medical intervention is appropriate as a result of preclinical or general medical experience. However, their reservations concerning the reward to be gained from working with elderly people were stable over the same periods, but were altered by a course in geriatric medicine.