To evaluate the changing patterns of complications of surgery for intersex, the records of 58 patients operated on for ambiguous genitalia over the last two decades were reviewed. Patients with 21-hydroxylase deficiency constitute the largest group. These patients required the fewest operations and had the fewest complications. Surgery for all other diagnoses was accompanied by a high incidence of multistaged procedures and a high complication rate. The operations associated with the highest complication rate were those for vaginal reconstruction and severe hypospadias. Stenosis of the vagina and urinary tract problems accounted for most of the problems. Before 1975, the management of intersex was associated with a later age at diagnosis and initial operation, and a higher incidence of multistaged procedures performed by multiple surgeons from different specialties. These factors contributed to a higher complication rate than that observed after 1975, when patients were diagnosed and operated on earlier and had fewer complications.