Behavioral disturbances occur in a majority of patients with neurologic disease and are substantial factors determining quality of life for such patients. Most of these difficulties can be treated safely and effectively. Yet behavioral signs and symptoms may go unnoticed or are minimized, incorrectly ascribed to a pre-existing psychiatric disorder, or misunderstood as “psychogenic” in origin. Working knowledge of brain-behavior relations helps clinicians understand associated behavioral disturbances as evidence of brain dysfunction. This summary relies on descriptive psychopathology to outline common disturbances in various behavioral domains and to consider their diagnostic implications.