HIV disease often leads to neuropsychiatric disturbance, either through direct infection of the brain by the virus or through CNS disease secondary to immunodeficiency. Neuropsychiatric complications of AIDS and AIDS-related disorders may present clinically as acute or chronic organic mental syndromes, or may mimic functional psychiatric illness, in particular depression, anxiety, or psychotic states. Two cases of hypomanic states in homosexual men suffering from AIDS are reported. Neither of the two men had a personal or family history of affective disorder. In one man, hypomanic symptoms were caused by early HIV encephalopathy; he rapidly developed typical HIV dementia with a marked downhill course. In the second case, a clear connection between the hypomanic symptoms and direct HIV brain involvement was not established.