When patients ascribe adverse symptoms to their medications, the medical care process can be affected. To investigate how often medical outpatients link various adverse symptoms with their medications and to learn what actions they take in response, 299 randomly selected medical outpatients were interviewed. Thirty percent of the subjects identified at least one medication as causing an undesirable symptom. Subjects 65 years or older attributed a lower mean number of adverse symptoms to their medications than did younger subjects. Subjects rarely reported modifying their medication regimens due to adverse symptoms, a finding supported by multiple regression analysis. Approximately one in four subjects did not discuss their symptoms with their providers. These results have important implications for medical care in general, and for the elderly in particular.