As part of a comprehensive multispecialty project, the present study reports on the neurocognitive and psychological function of veterans who report Persian Gulf War-related symptoms. The neuropsychological and psychological performances of 26 ill Gulf War veterans were compared to 20 well veterans from the same military unit. Neurocognitive functions assessed included intelligence, abstraction and problem-solving, attention and concentration, memory and learning, language and visual-spatial function, and sensorimotor abilities. Psychological function was measured by self-report questionnaires. Results indicated global and consistently poorer intellectual and neurocognitive function among the ill veterans compared to the control veterans. A generalized pattern of neuropsychological deficit was evident for the ill veterans. Psychological profiles of the ill veterans were similar to those in general medical patients. Based on these findings and results from the multispecialty investigation, we conclude that some of the ill veterans have experienced neurotoxic injury resulting in chronic neuropsychological impairment that is related to their service in the Persian Gulf War.