- Endometriosis is a common gynecologic disease of unknown etiology affecting approximately 10-15% of women of reproductive age and 50% of infertile women. Estrogen dependence and immune modulation are established features of endometriosis but do not adequately explain the cause of this disorder. In recent years evidence indicated that exposure to environmental toxicants possessing estrogenic activity resulted in endometriosis. However, scant hospital-based case-control studies yielded inconsistent findings and thus did not provide a compelling argument for or against an association between environmental toxicant exposure and endometriosis. Results of animal studies and cell culture experiments, however, suggested that it is biologically plausible for environmental toxicants to affect the pathobiology of endometriosis. In this article, the literature linking environmental toxicants with endometriosis was reviewed and the link with endocrine toxicants discussed.