Polycystic ovary syndrome (PCOS) is a common reproductive endocrinology disease with heterogeneous phenotype. Environmental factors are thought to be involved in the development of PCOS. The present study aimed to explore the potential environmental risk factors of PCOS. A cross-sectional study and stratified population-based case-control study were carried out. Pre-designed questionnaires were prepared, including questions about medication history, contact history of endocrine disruptors (EDs), environment and habituation. Fasting blood was collected for measurement of sex hormone, glucose and insulin. Matched logistic regression analysis was used to find the potential independent risk factor of PCOS. One thousand eight hundred fifty-four participants (aged 12-44 years) were analyzed in the cross-sectional investigation. One hundred sixty-nine PCOS patients and 338 matched controls were compared. PCOS patients were more frequent than controls in eating plastic-packaged food (p=0.001), contacting pesticide (p=0.021), eating fruit with pericarp (p=0.001), living beside a garbage heap (p=0.001), working at an acid plant (p=0.028), taking Chinese patent drugs (p=0.001), smoking (p=0.028) and drinking alcohol (p=0.001). However, PCOS patients were less likely to use kitchen ventilators (p=0.002), eat canned food (p=0.049), contact decorated materials, use skin care products (p=0.01) and cosmetics (p=0.027). No difference was found in taking antiepileptic drugs (p=0.93). Eating plastic-packaged food (p=0.001, OR=44.449), eating fruit with pericarp (p=0.03, OR=5.7) and drinking alcohol (p=0.001, OR=29.632) were found to be the independent risk factors for PCOS. The existence of an association between EDs and PCOS was proved. Plastic-packaged food, fruit with pericarp and drinking alcohol should be avoided as possible as we can. However, the causal relationships among these factors and PCOS should be proved by further research.