Objective: To propose an etiological model of antisocial personality disorder that is grounded in empirical data. Method: Recent research findings are reviewed that clarify our understanding of the etiology and course of antisocial pathology. Results: Neither biological nor psychological factors fully account for the development of this disorder. Epidemiological studies show that there are strong cross-cultural differences in its prevalence, pointing to the importance of social factors in its etiology. Outcome research shows that antisocial personality only partially remits with time, and that most patients continue to be dysfunctional in later life. No treatment modality has been shown to be effective. Conclusions: All these empirical findings can be accounted for by a biopsychosocial model of antisocial personality disorder.