OBJECTIVES: The overall incidence of breast cancer is lower in African American (AA) women in comparison to European American (EA) women; however AA women are more likely to die of the disease. National data has reported that compared to EA women, AA women have a poorer diet quality and are also among the highest consumers of added sugar. This analysis aims to explore the association of carbohydrate intake and breast cancer risk among AA and EA women.   METHODS: We evaluated the association in a case-control study including cases (breast cancer positive) and controls (cancer negative). Food consumption was collected using a Food Frequency Questionnaire. Multivariable logistic regression controlling for relevant breast cancer risk factors was used to calculate Odd Ratios (OR) and 95% Confidence Intervals (CI).  RESULTS: Our sample size was 3148. Overall, EA women who consumed larger amounts of total carbohydrates (highest quartile) had a significantly decreased risk of breast cancer compared to those who consumed lower amounts of total carbohydrates (lowest quartile) OR=0.60; 95% CI: 0.43-0.83. In stratified analyses, a stronger inverse relationship was noted amongst premenopausal EA women for total carbohydrates (OR=0.48; 95% CI: 0.30-0.78) and added sugars (OR=0.56; 95% CI: 0.35-0.89). Additionally in EA women with ER+ tumors, there was a significantly decreased risk of breast cancer for those who consumed larger amounts of total carbohydrates. For AA women, we found no evidence of an association for total carbohydrates, glycemic load or added sugars.  CONCLUSIONS: This study suggested an inverse association between carbohydrate consumption and breast cancer risk in EA women, particularly for those premenopausal and with ER+ tumors. However, we could not establish and association between carbohydrate consumption and breast cancer risk in AA women. Moreover, the specific types of carbohydrates and food sources need be studied for both EA and AA women to better understand the association.