Background & Aims: Insulin resistance has been implicated in the pathogenesis of both nonalcoholic fatty liver disease (NAFLD) and polycystic ovary syndrome (PCOS). We hypothesized that NAFLD would be common in both obese and nonobese women with PCOS. The aim of this study was to estimate the prevalence of and identify associated factors for hepatic steatosis in women with PCOS. Methods: This is a retrospective study of 88 consecutive premenopausal women with PCOS. Clinical history, height, weight, and laboratory values were obtained. Fasting measurements of serum glucose and insulin were used to calculate homeostasis model assessment of insulin resistance (HOMA-IR). Abdominal ultrasonography was used to determine the presence and severity of hepatic steatosis. Results: Of the 88 women (median age, 31.4 years), 48 (55%) had steatosis; 15 (39%) of them were lean women. The presence of steatosis was associated with a greater body mass index (BMI) (P = .005) and HOMA-IR (P = .033), a lower fasting high-density lipoprotein (P = .003), and a greater prevalence of impaired fasting glucose, impaired glucose tolerance, and diabetes mellitus (P = .013). Only 7 (15%) subjects with hepatic steatosis had abnormal liver chemistries. Conclusions: Fatty liver was identified in 55% of subjects with PCOS, nearly 40% of whom were lean women. High BMI and insulin resistance appeared to be important associated factors. Early recognition of NAFLD in this group of young patients is warranted, and further investigation including liver biopsy might be indicated.