OBJECTIVES: To identify and study adults (21 years or older) who have a 46,XY karyotype and presented as infants or children with genital ambiguity, including a small phallus and perineoscrotal hypospadias, reared male or female. METHODS: Participants were classified according to the cause underlying their intersex condition based on review of medical and surgical records. Long-term medical and surgical outcome was assessed with a written questionnaire and physical examination. Long-term psychosexual development was assessed with a written questionnaire and semistructured interview. RESULTS: Thirty-nine (72%) of 54 eligible patients participated. The cause underlying genital ambiguity of participants included partial androgen insensitivity syndrome (n = 14; 5 men and 9 women), partial gonadal dysgenesis (n = 11; 7 men and 4 women), and other intersex conditions. Men had significantly more genital surgeries (mean: 5.8) than women (mean: 2.1), and physician-rated cosmetic appearance of the genitalia was significantly worse for men than for women. The majority of participants were satisfied with their body image, and men and women did not differ on this measure. Most men (90%) and women (83%) had sexual experience with a partner. Men and women did not differ in their satisfaction with their sexual function. The majority of participants were exclusively heterosexual, and men considered themselves to be masculine and women considered themselves to be feminine. Finally, 23% of participants (5 men and 4 women) were dissatisfied with their sex of rearing determined by their parents and physicians. CONCLUSIONS: Either male or female sex of rearing can lead to successful long-term outcome for the majority of cases of severe genital ambiguity in 46,XY individuals. We discuss factors that should be considered by parents and physicians when deciding on a sex of rearing for such infants.