Proper gender assignment to a neonate born with ambiguous genitalia is a social emergency of the newborn period. Once an appropriate sex assignment has been made, the next critical step is performance, if needed, of a reconstructive procedure in a timely fashion. In an attempt to evaluate our experience with this unique group of patients, we have retrospectively reviewed the course of 69 children with ambiguous genitalia managed surgically at this institution between 1974 and 1989. This series consists of 32 genotypic females with congenital adrenal hyperplasia (CAH), 10 children with mixed gonadal dysgenesis (MGD), 10 male pseudohermaphrodites, 3 true hermaphrodites, 8 genotypic females with urogenital sinus anomalies (UGS), and 6 genotypic males with bilateral undescended testes and penoscrotal hypospadius. All newborns initially seen at this institution received proper sex assignment within the first week of life. Prior to 1980, 17 of the children with CAH underwent clitorectomy and vaginoplasty and three underwent clitoral recession and vaginoplasty. After 1980, 10 patients with CAH were managed with clitoral recession and vaginoplasty and 2 with vaginoplasty alone. Eight of 10 cases of MGD were given a female sex assignment and all 8 underwent gonadectomy due to the high risk of gonadoblastoma; the other 2 children were raised as males. There were 3 true hermaphrodites of which 2 were assigned female gender roles and were managed with a clitoral recession and vaginoplasty. All 10 male pseudohermaphrodites were raised as females and all underwent bilateral orchidectomy. The 8 children with UGS were raised as females and underwent vaginal reconstruction.(ABSTRACT TRUNCATED AT 250 WORDS)