In the present study, we examined the effect of repeated and long-term treatment with resveratrol on NO production in endothelial cells as a model of routine wine consumption. Repeated treatment with resveratrol for 5 d resulted in an increase in endothelial NO synthase (eNOS) protein content and NO production in human umbilical vein endothelial cell (HUVEC) in a concentration-dependent manner. A significant increase in functional eNOS protein content was observed with resveratrol, even at 50 nm. In contrast, eNOS phosphorylation was not stimulated and inducible NO synthase (iNOS) was not detected after resveratrol treatment. Both eNOS protein and mRNA expression were promoted by 50 nm-resveratrol in a time-dependent manner. Increased eNOS mRNA expression in response to resveratrol was not decreased by an oestrogen receptor (ER) antagonist ICI182780, a PPARα inhibitor MK886 or a sirtuin inhibitor Salermide. However, a combination of ICI182780 and MK886 significantly inhibited resveratrol-induced eNOS mRNA expression. Salermide had no effect even in the presence of ICI182780 or MK886. These results demonstrate that resveratrol within the physiological range increases eNOS mRNA and protein expression through ER and PPARα activation, thereby promoting NO production in endothelial cells. eNOS induction might result from the accumulative effect of nanomolar concentrations of resveratrol. The present study results can account in part for the observation that cardiovascular benefits of red wine are experienced with routine consumption, but not with acute consumption.