Impairments of social behavior after cerebral damage are often problematic and difficult to assess and manage, with few models addressing evaluation, treatment options and prognosis. Recent studies suggest that a fundamental mechanism of social behavior disturbed by acquired cerebral damage is empathy. Empathy refers to the cognitive and emotional processes that bind people together in various kinds of relationships that permit sharing of experiences as well as understanding of others. Empathic changes are particularly evident after focal prefrontal cortex damage and closed head injury in adults, though early frontal lobe damage is also associated with poor empathic and social development. Although alterations in empathy have been studied in only a handful of neurologic samples thus far, it may be an important outcome variable of brain injury, particularly in patients' adjustment to family, community and vocational settings. Treatment possibilities are presented, though more comprehensive research is needed.