Study summary: The present study was designed to evaluate the association between dietary and supplemental intakes of carotenoids and vitamins C and E and the risk of breast cancer according to estrogen receptor (ER) and progesterone receptor (PR) status. The study group included 84,805 postmenopausal women in the Women's Health Initiative Observational Study. During an average follow-up period of 7.6 years, there were 2,879 new cases of invasive breast cancer, of which 2,509 had receptor data. Dietary α-carotene (highest versus lowest quintile: RR = 0.83; 95% CI = 0.70- 0.99; P for trend = 0.019), β-carotene (highest versus lowest quintile: RR = 0.78; 95% CI = 0.66-0.94; P = 0.021), and lycopene (highest versus lowest quintile: RR = 0.85; 95% CI = 0.73-1.00; P = 0.064) were each found to be inversely associated with the risk of ER+/PR+ breast cancer, but not with other breast cancer groups as defined by ER and PR status. Total or supplemental β-carotene and dietary intakes of lutein+zeaxanthin and β-cryptoxanthin were not found to be associated with breast cancers defined by ER and PR status. Vitamin E (regardless of source) and dietary vitamin C were found not to be associated with breast cancer. However, both total (dietary plus supplemental) and supplemental vitamin C intake were found to be weakly positively associated with breast cancer. The authors conclude that dietary intake of certain carotenoids might be differentially associated with risk of invasive breast cancers jointly defined by ER and PR status among postmenopausal women.