OBJECTIVE To evaluate the effects of selegiline on behavioral and cognitive symptoms of patients with Alzheimer disease. METHODS An English-language MEDLINE search (1982-1995) was used to identify the review articles and human clinical trials discussed in this article. METHODS Double- and single-blind and open-label trials were reviewed. Studies were also reviewed if selegiline was evaluated comparatively with other agents. Review articles were used for background information. METHODS Data were evaluated from human studies. Studies were critiqued on the basis of design, methodology, duration, sample size, and the degree to which neuropsychological tests used in each study were compared. RESULTS Selegiline is a selective, irreversible inhibitor of monoamine oxidase type B. Eight of 11 controlled trials showed selegiline had a positive effect on cognition (e.g., word fluency, delayed recall, total recall). Two of 5 controlled trials evaluating selegiline's effect on behavior (e.g., anxiety, tension, excitement, depression) showed a positive effect. CONCLUSIONS The role of selegiline remains to be determined by large well-controlled long-term clinical trials. Selegiline may be a useful agent in managing behavioral and cognitive symptomatology associated with Alzheimer disease. Given that the management of Alzheimer disease is symptomatic and no standard treatment exists, selegiline should be considered among the various options.