Amnesia is a common clinical problem characterized by four features: (1) normal immediate recall, (2) impaired ability to learn, (3) relatively spared ability to retrieve previously learned material, and (4) preserved cognitive and personality characteristics. Amnesia occurs as a distinct mental disorder, and nine variations seen clinically are described here: Korsakoff's psychosis, posttraumatic amnesia, amnesic stroke, postoperative amnesia, postinfectious amnesia, anoxic amnesia, transient global amnesia, amnesia following ECT, and psychogenic amnesia. The clinical findings which characterize and differentiate these disorders are presented, along with suggestions for management and a discussion of the outcome of anmesia.