To assess attitudes and practices regarding screening tests and preventive procedures, we surveyed 83 physicians in a hospital-based ambulatory care practice and compared their recommendations with the recommendations in published guidelines, the desires of 188 of their own patients, and the physicians' actual practice patterns on the surveyed patients. The surveyed physicians recommended screening procedures more frequently than the published guidelines in 48 situations and less frequently in 18 situations. Physicians at earlier levels of training tended to recommend more procedures than those who had completed training. Patients desired far more frequent screening than recommended either by their physicians or by the published guidelines. Physicians did not live up to their own recommendations for four of 14 procedures or to published guidelines for five of 14 procedures, with such failure occurring principally in situations where the test or procedure would normally be done personally by the physician.