This paper describes patients whose mental illness manifests itself in association with becoming a father. Besides such factors as dependency on the wife (mother) and resentment of the intruder, the following sources of anxiety are discussed: 1, guilt associated with aggressive impulses toward the wife and baby, which reactivates earlier aggressive feelings toward the patient's own mother, father, or sibling; 2, pregnancy envy, particularly in psychotic males who have believed they were pregnant; 3, reactivation of the Oedipus complex in men whose sense of maleness is poorly developed, the denial of fatherhood being the defense in some cases against the incestuous crime; 4, deep unconscious concerns regarding masculinity and the consequences of potency in patients who