Objective:To determine the nature, frequency and effects of internal medicine bousestaff and faculty contacts with pharmaceutical representatives (PRs). Design and setting:The authors surveyed internal medicine faculty at seven midwest teaching hospitals and housestaff from two of the teaching programs. The survey asked about type and frequency of contacts with PRs and behavior that might be related to these contacts. T-tests and logistic regression were used to estimate the relationship between reported physician contacts and behavioral changes. Participants:Two hundred forty faculty (78%) and 131 house officers (75%) responded to the survey. Results:Faculty and housestaff averaged 1.5 brief contacts per month with PRs. Housestaff averaged more than one meal/month at pharmaceutical company expense. Twenty-five percent of faculty and 32% of residents reported changing their practices at least once based on PR contact. Independent predictors of faculty change in practice were brief or extended conversations and free meals. Predictors of faculty requests for formulary addition were brief conversations and receipt of honoraria or research support. Only brief conversations independently predicted housestaff changes in practice. Conclusion:Academic housestaff and faculty have frequent PR contact; such contact is related to changes in behavior. The potential for influence of PRs in academic medical centers should be recognized, and their activities should be evaluated accordingly.