To investigate the association between breast cancer risk and nutrient intake in Korean women, a case-control study was carried out. Incident cases (n=224) were identified through cancer biopsy between february 1999 and December 2000 at two university hospitals in Seoul. Hospital-based controls (n=250) were selected from patients in the same hospitals, during the same periods. food intake was investigated with semi-quantitative food frequency questionnaire (98 items) by a trained dietitian. Subjects were asked to indicate the average intake, for a 12-month period of three years prior to the baseline phase. In this study, no apparent association was found between fat intake level and breast cancer risk. High fiber intake showed a significant inverse association only among premenopausal women. In terms of antioxidant vitamins, $eta$-carotene and vitamin C among premenopausal women and vitamin C intake among postmenopausal women was significantly associated with a decreasing risk of breast cancer. A protective effect of high calcium consumption was observed among postmenopausal women. In conclusion, our findings support epidemiological evidence that antioxidant vitamin intake could lower the breast cancer risk in Korea.