A follow-up study of 8370 outpatients who filled over 24,000 prescriptions for tolmetin revealed no hospital admissions for acute allergic, blood, skin, or central nervous system illness within 90 days of filling a prescription or refill for the drug. There were two cases of liver disease and two cases of nephrotic syndrome in which an etiologic relationship to tolmetin seemed unlikely but could not be entirely ruled out. In addition, 11 patients were hospitalized for peptic ulcer disease and its complications. In all but two patients other risk factors were present that could readily explain the illness. The rate of hospitalization for peptic ulcer disease and its complications among tolmetin recipients appears to be of the same magnitude as that in patients who take other nonsteroidal antiinflammatory drugs in this population, and close to that of the population at large.