The illnesses requiring surgery are among the most strenuous adversities of aging. The decision to operate upon an elderly person must take into account the stress the experience will imposed upon the cardiovascular, metabolic, and other systems which, with less resiliency than in earlier years, will have to adapt to the effects of anesthesia, tissue damage, and the strain of postoperative restoration of somatic function. The surgical experience is also a threat to the integrity of the aging nervous system and to the elderly patient's psychological adaptation. Our research team has had the opportunity of intensive observation of a number of aged people who became ill and were admitted to a surgical service for treatment. We have assembled data that contribute to an understanding of the psychological responses of the aged person to surgery. Concentration upon the psychologically stressful aspects of surgery from a perspective of the therapeutic value of