To evaluate the reproductive consequences of prenatal diethylstilbestrol (DES) exposure, 33 infertile couples were studied in whom the female had been exposed to DES in utero. Infertility was attributed to uterotubal junction obstruction in 3 couples, anovulation in 7, endometriosis in 11, cervical obstruction in 2, adnexal adhesions in 2, oligospermia in 1 and luteal insufficiency in 3; in 4 couples no cause of infertility could be identified. No unique intraabdominal abnormalities attributable to DES exposure were observed. Four tubal pregnancies occurred in women with grossly normal oviducts. Nine of 11 women who had previously undergone surgical manipulation of the cervix (cryosurgery, cautery or conization) developed cervical stenosis, and 8 of them were found to have endometriosis. Despite our not having an appropriate referral infertility population for comparison, these findings are consistent with the following hypotheses regarding women prenatally exposed to DES: (1) surgical manipulation of the cervix more frequently leads to cervical stenosis and ultimately pelvic endometriosis, (2) tubal pregnancies may occur by a mechanism unrelated to salpingitis, and (3) the spectrum of problems causing infertility is similar to that in the non-DES-exposed population.