Resveratrol (3,4',5-trihydroxy-trans-stilbene) is a common phytoalexin that is found in a few edible materials, such as grape skins, peanuts, and red wine. It has been speculated that dietary resveratrol may act as an antioxidant, promote nitric oxide production, inhibit platelet aggregation, and increase high-density lipoprotein cholesterol, and thereby serve as a cardioprotective agent. Based on epidemiological data, carcinogenesis and coronary heart disease are linked to dietary lifestyle and share a number of common pathways. Recently, it has been demonstrated that resveratrol can function as a cancer chemopreventive agent, and there has been a great deal of experimental effort directed toward defining this effect. Resveratrol has been reported to be estrogenic in transfected mammary cancer cells; however, there are conflicting results with respect to its actual estrogenic properties. In addition, resveratrol exhibits antiinflammatory, neuroprotective, and antiviral properties. In future work, some controversial in vitro biological effects need to be explored in animal models, and relevant physiological and pharmacological concentrations need to be used when assessing biological activities. This review focuses on various biological aspects of resveratrol and some issues that need to be addressed to gain a fuller appreciation of potential health benefits for human beings.