Eight patients with intracranial cysts presenting with primary psychiatric diagnoses were studied. The cysts were visible on computed tomography (CT) and magnetic resonance imaging (MRI), and they produced neurologic, electroencephalographic (EEG), and neuropsychologic abnormalities. Descriptions of psychiatric manifestations associated with intracranial cysts are rare, and their potential neuropsychiatric significance has been minimized. This study demonstrates that intracranial cysts can cause neuropsychiatric symptoms, that surgical intervention may resolve the psychiatric manifestations in selected cases, and, in cases not warranting surgery, that psychopharmacological therapy to treat the behavioral manifestations is indicated. These cases mandate consideration of intracranial cysts in the diagnostic and therapeutic formulation of atypical neuropsychiatric disorders.