Whole grain consumption has long been associated with human health. However, its relationship with breast cancer remains not well understood and appreciated. The aim of this work was to evaluate the association between whole grain consumption and breast cancer in women.A case-control study was designed. Two hundred and fifty consecutive, newly diagnosed breast cancer female patients (56 ± 12 years) and 250 one-to-one age-matched controls were enrolled. A standardized, validated questionnaire assessing various sociodemographic, clinical, lifestyle, and dietary characteristics was applied through face-to-face interviews. Moreover, data on regular consumption of whole grains (i.e., never/rarely, 1-6 times/week, >7 times/week) were recorded. Overall dietary habits were assessed through the level of adherence to the Mediterranean diet using the MedDietScore (theoretical range 0-55).Whole grain consumption of more than 7 times/week was associated with a 0.49-fold (odds ratio = 0.49; 95% confidence interval, 0.29, 0.82) lower likelihood of having breast cancer, after adjustments were made.This study suggested that whole grain consumption more than 7 times/week was consistently associated with reduced risk of breast cancer.