We found detectable levels of three phytoestrogens (enterolactone, daidzein and genistein) and bisphenol A (BPA) in 21 residual amniotic fluid specimens that were collected before 20 weeks gestation. Samples were obtained by amniocentesis from women who were referred to the Mount Sinai Medical center because of advanced maternal age. Phytoestrogens were present in higher concentrations than BPA. Enterolactone was detected at the highest concentration (median 95.9 microg/L), followed by daidzein and genistein (9.5 and 1.4 microg/L, respectively). BPA was present at very low concentrations (10%>LOD of 0.5 microg/L). The relative concentration of the chemicals measured in amniotic fluid were identical to those in urine reported by other studies, i.e. enterolactone>daidzein>genistein>>BPA. Amniotic fluid is a source of fetal exposure to polar xenobiotics that come from the mother.