PURPOSE: The purpose of this study was to investigate the relationship between dietary flavonoids intake and metabolic syndrome (MetS) in Korean women with polycystic ovary syndrome (PCOS). METHODS: A total of 223 subjects (mean age; 27.3 +/- 4.2 yrs, range; 17-38 yrs) were divided into the MetS group (n = 27) and non-MetS group (n = 196). Dietary intake data were assessed by 24-hour recall method for two non-consecutive days and the average of the two days was used to estimate the usual dietary intake. Dietary habits were assessed using the Mini Dietary Assessment (MDA) score. We analyzed the intakes of six flavonoid classes (anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols, and iso-flavones) using a flavonoids database. RESULTS: After adjustment for age, total energy intake, alcohol consumption, smok-ing, regular exercise, and oral contraceptive use, dietary flavonols intake was significantly lower in the MetS group (5.1 +/- 2.4 mg/d) than in the non-MetS group (8.9 +/- 2.8 mg/d) (p = 0.0472). Intakes of other flavonoids except for flavonols did not differ between the two groups. In MDA scores, significant differences were observed only for that related to daily con-sumption of fruit or fruit juice (p = 0.0180). A significant inverse relationship was observed between flavonols intake and the risk of MetS (4th vs. 1st quartile, OR = 0.11, 95% CI = 0.02-0.62, p for trend = 0.0131). CONCLUSION: These results sug-gest that higher intake of flavonols may be beneficial for MetS in PCOS women.