Several decades ago, diethylstilbestrol (DES) was prescribed to support the pregnancy of women who were diabetic, who had had consecutive abortions, or who were threatening to abort. The use of this estrogen substitute to support human gestation had ceased by the 1960s. In 1971, the first report was published in which DES exposure was linked with clear cell carcinoma of the vagina and cervix. Since then, many other documentations have been published on upper genital tract anomalies, poor reproductive performance, and the high incidence of fetal wastage in DES-exposed women. The author describes a case of clear cell carcinoma of the kidney in an 18-year-old pregnant woman with a prior history of vaginal adenosis who had been exposed to DES in utero.