Dietary folate deficiency may contribute to tumorogenesis in many sorts of malignancies. By considering the increasing incidence rate of breast cancer in Iran, this study was conducted to investigate the association between dietary folate intake and breast cancer risk. In this case-control study, 177 patients with breast cancer and 169 control subjects with no family history of malignancy were recruited from hospitals affiliated to Shahid-Beheshti University of Medical Sciences, Tehran. Standard questionnaires were used to collect data on demographic characteristics, physical activity, and food frequency consumption for the previous year. Total daily energy and folate intakes were estimated using the Nutritionist IV software. No statistically significant correlation was observed between daily dietary intake of folate and breast cancer risk in the sample population. However, the results showed a significant inverse association between daily intake of dietary folate and risk of breast cancer in postmenopausal women (OR= 0.17 95% CI: 0.035-0.88). Increases in the strata of daily folate intakes were associated with decreasing trends of ORs in postmenopausal breast cancer risk (Pfor trend= 0.036), where the OR of folate intake at the 2nd tertile was 0.26 (95% CI: 0.05-1.22) and at the 3rd tertile was 0.17 (95% CI: 0.035-0.88). Based on the findings, folate intake was not correlated with breast cancer risk in the total sample population, whereas higher intakes of folate was inversely associated with postmenopausal breast cancer risk. Keywords: Folate, Dietary intake, Breast cancer, Case-control, Food frequency questionnaire