An analysis of every tenth case record from each year of birth and for both sexes from a patient list in a practice with three partners showed that 13% of patients who attended the health centre at least twice a year had usually consulted a trainee. These patients were usually young adults, free from known important long term health problems, and they had closely similar clinical characteristics to those patients who did not usually consult the same principal. Few patients usually consulted each trainee over three years.