Abstract Background: Several studies have examined associations between breast cancer risk and individual foods and nutrients. Most studies have evaluated risks associated with individual foods and nutrients, rather than measures of whole-diet. The objective of this study was to investigate the association between dietary patterns and the risk for breast cancer. Methods: A total of 93,306 women aged 40-69 years were enrolled in the prospective cohort study in the Health Examinees-Gem (HEXA-G) study between 2004 and 2013. Information on cancer diagnosis in the eligible cohort was retrieved from the Korea Central Cancer Registry through 31 December 2014. Dietary patterns were identified using factor analysis of data from a 106-item validated food frequency questionnaire. We conducted a multivariable Cox regression model to obtain the hazard ratio (HR) and 95% confidence interval (CI) for the risk of breast cancer according to the dietary pattern scores. Results: A total of 359 incident cases of breast cancer occurred over an average follow-up period of 6.3 years. Using a factor analysis, we identified three major dietary patterns, which explained 23.9% of the total variance, based on the daily total food intake (g/day) from 37 food groups: the Vegetables and seaweed pattern (greater intake of yellow-green and other vegetables, seaweed, lean fish, and shellfish), the Flour and meat pattern (greater intake of bread, pizza and hamburger, red meat, and poultry), the White rice and salt fermented fish pattern (greater intake of white rice and salt fermented fish). We found that the women who had higher white rice and salt fermented fish pattern scores tend to have higher risk of breast cancer. Multivariate HR (95% CI) comparing the highest with the lowest quintiles of White rice and salt fermented fish pattern scores was 1.35 (1.00, 1.84) (p for trend = 0.0384). Other two dietary patterns, the Vegetables and seaweed pattern and the Flour and meat pattern, showed no significant association with the breast cancer risk for women. Conclusion: The White rice and salt fermented fish pattern was associated with a increased risk of breast cancer, but further investigation involving subgroup analysis is warranted. Citation Format: Woo-Kyoung Shin, Hwi-Won Lee, Aesun Shin, Jong-koo Lee, Daehee Kang. Multi-grain rice diet decreases risk of breast cancer in Korean women: Results from the Health Examinees study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-279.