A patient, S., voiced the opinion that subnormals, the blind, anyone with physical or mental imperfections should be exterminated. This included the psychiatrically ill and consequently himself. He had attempted suicide, and said that when he thought it appropriate he would attempt suicide again. In projective tests and interviews he expressed the wish to kill his father, and showed much sado-sexual fantasy and racial prejudice. Psychological tests showed that he was of average intelligence, non-retarded and abnormally overinclusive. He was diagnosed initially as “paranoid schizophrenic”. Such bizarre and macabre features are not necessarily dangerous, but S. was married with two young children. He believed his children to be highly intelligent. Another baby was expected shortly. This study attempted to predict whether these attitudes were potentially dangerous should the patient discover some imperfection in his family.