OBJECTIVE The outcome of in vitro fertilization (IVF) in a group of infertile women with a history of in utero exposure to diethylstilbestrol (DES) was analyzed. Records from an academic IVF program were retrospectively reviewed. METHODS Seventeen infertile women with a self-reported history of exposure to DES in utero, attending the IVF unit at Massachusetts General Hospital (MGH) for assisted reproductive technology (ART), underwent 27 IVF cycles. Analysis of the outcome of IVF including implantation and ongoing pregnancy rates was performed. The data were compared with results from a group of 20 infertile patients with idiopathic infertility undergoing 27 IVF cycles at MGH during the same period. The patients in the two groups were matched for age, basal day 3 levels of follicle stimulating hormone and serum estradiol, and the number and quality of embryos transferred. RESULTS The response to controlled ovarian hyperstimulation was comparable in the two groups. Significantly lower implantation and ongoing pregnancy rates following IVF and embryo transfer were seen in the utero DES-exposed group compared to the control patients. CONCLUSIONS Infertile patients with a history of in utero exposure to DES exhibit a significantly impaired implantation rate following IVF, and the outcome of ART remains poor.