Resveratrol is a non-flavonoid polyphenol that has attracted attention as a potential anticancer agent in vitro and in vivo, but scanty epidemiological data are available. We have therefore analysed the relation between dietary intake of resveratrol and breast cancer risk using data from a case-control study conducted between 1993 and 2003 in the Swiss Canton of Vaud on 369 cases and 602 controls. Compared with the lowest tertile of total resveratrol intake, the multivariate odds ratios (OR) were 0.50 for the intermediate and 0.39 for the highest tertile, and the trend in risk was significant. A significant inverse association was observed for resveratrol from grapes (OR = 0.64 and 0.55), but not for wine. The inverse relation between resveratrol and breast cancer risk was not explained by several potential confounding factors, including detailed allowance for alcohol intake, nor attributable to a non-specific favourable effect of fruit on breast cancer risk.