Prenatal diethylstilbestrol (DES) exposure in pregnancy has been associated with adenocarcinoma of the vagina and/or cervix as well as teratogenic abnormalities of the genital tract in both female and male offspring. DES Action groups are alerting the public to the dangers inherent in being a `DES daughter' or a `DES son'. Family physicians must be able to reassure those patients who are not DES offspring, manage those who are, and detect those who didn't know they were. The screening and management of DES problems, including history-taking, physical examination, relevant laboratory exams and consultation for diagnosis and treatment of both male and female patients are discussed. In addition, psychological support, patient education, longterm follow up, the management of contraception and pregnancy in DES daughters, and infertility in DES sons are considered.