Breast cancer (BC) is a multifactorial disease. Environmental factors, specifically, obesity and diet quality, have been linked with an increased risk of BC in women. This research was aimed at assessing the association of diet quality with BC risk, considering nutritional status, in Córdoba province (Argentina). A case-control study was conducted during the period 2008-2016 (346 cases/566 controls). A diet quality score was calculated for each woman based on fifteen dietary components related to low-grade inflammation. Dietary information was obtained through a validated questionnaire. A score (0, 0.5, or 1) was assigned to each variable depending on compliance with dietary recommendations. The higher the score, the higher the degree of adherence to a poor quality diet, which carries a potential inflammatory effect. A multiple logistic regression analysis was used to assess the association between BC occurrence and diet quality, adjusting by body mass index. The mean score of women was 6.86 (1.83). Of total women studied, 20% were obese. A 39% increase in BC risk was observed for each unit of increase in the score in this group (Odds Ratio: 1.39; 95% Confidence Interval: 1086-1796). Obese women with poorer quality diet have a greater risk of BC occurrence in Córdoba (Argentina).