Psychopathological reactions to fatherhood are probably not so infrequent as they would seem from psychiatric literature. In a material of paranoid psychoses, impending or newly established fatherhood was considered the main precipitating factor in 4 patients (i.e. 2.4%), compared with 7% of the female psychoses precipitated by pregnancy, childbirth or nursing. Two of the men were batchelors, insecure and inhibited, feeling compromised or helpless in the new situation. Two men were married, passive, avoidant in their personality, strongly dependent on their wives. The course and outcome varied according to the diagnoses; 2 cases having a favorable and 2 an unfavorable course and outcome. Physicians, including psychiatrists, should bear in mind that fatherhood is a possible precipitating factor for paranoid psychoses in male patients.