Aflatoxin B₁ (AFB₁) has been consistently shown to be a potent mutagen and carcinogen in humans and animals. On the other hand, resveratrol (RSV), a polyphenol, has several positive biological actions such as protection of cells against DNA damage. In the present study, the antigenotoxic effect of RSV was studied against a genotoxic dose of AFB₁ using the damage parameters of chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs) in cultured human lymphocytes. Whole blood samples from three healthy male donors were used for this experiment and the effects of various concentrations of RSV (0, 10, 15, 25, 40, 75 and 100 µM) and AFB₁ (10 µM) were tested. The results revealed that the frequencies of SCEs and CAs in lymphocytes were significantly (p < 0.05) increased by AFB₁ as compared to controls. The results also showed that RSV was not genotoxic. Moreover, the number of SCEs and micronuclei induced by AFB₁ could be significantly minimized by the presence of RSV. Our results suggest for the first time that RSV can antagonize the ability of AFB₁ to cause DNA damage that leads to the formation of SCEs and CAs.