Purpose. To provide an introduction to evolutionary psychology by describing some of its applications in the literature on the psychology of criminal and antisocial behaviour.Argument. Selectionist thinking is applied to five areas: the relationship of age and sex to crime, the inverse correlation between degree of kinship and homicide, paedophilia, persistent antisociality, and sexual coercion. In each of these areas, ultimate causes of behaviour are distinguished from proximal causes. Ultimate causes are produced by selective forces in ancestral environments and are responsible for species typical characteristics. Proximal causes, in contrast, are contemporaneous developmental, genetic, and environmental determinants of behaviour.Conclusions. The interplay between ultimate and proximal causation provides new ways of understanding old problems and is a fruitful source of research hypotheses. Evolutionary psychology can provide a powerful integrative perspective on criminal and antisocial behaviour.