As the population of aging physicians increases, methods of assessing physicians' cognitive function and predicting clinically significant changes in clinical performance become increasingly important. Although several approaches have been suggested, no evaluation system is accepted or utilized widely. This article reviews literature using MEDLINE, PubMed, and other sources. Articles discussing the problems of geriatric physicians are summarized, stressing publications that proposed methods of evaluation. Selected literature on evaluating aging pilots also was reviewed, and potential applications for physician evaluation are proposed. Neuropsychological cognitive test protocols were summarized, and a reduced evaluation protocol is proposed for interdisciplinary longitudinal research. Although there are several articles evaluating cognitive function in aging physicians and aging pilots, and although a few institutions have instituted cognitive evaluation, there are no longitudinal data assessing cognitive function in physicians over time or correlating them with performance. Valid, reliable testing of cognitive function of physicians is needed. In order to understand its predictive value, physicians should be tested over time starting when they are young, and results should be correlated with physician performance. Early testing is needed to determine whether cognitive deficits are age-related or long-standing. A multi-institutional study over many years is proposed. Additional assessments of other factors such as manual dexterity (perhaps using simulators) and physician frailty are recommended.