Evolutionary theory has had a major impact on psychiatry since the middle of the 19th century. During the Nazi regime psychiatry supported compulsory sterilization and euthanasia of physically and mentally ill and subsequently the killing of "inferior" races by borrowing scientifically invalid conclusions from evolutionary biology. The present paper deals with some of the flaws and shortcomings of the scientific paradigms of evolutionary theory adopted by psychiatry during the Nazi regime and discusses possible implications for modern research in evolutionary psychology and psychiatry.