The aim of this study was to investigate the effects of carnosine, a biological antioxidant, on the oxidative stress and genotoxicity by a single dose of carbon tetrachloride (CCl(4); 5 mM) in the human lymphocyte culture. We studied the anti-genotoxic effects of carnosine by using sister chromatid exchange (SCE) test system. Also, the anti-oxidative effects of carnosine were evaluated by using superoxide dismutase (SOD), glutathione peroxidase (GPx), total glutathione (GSH) and malondialdehyde (MDA) assay. The SCE frequency was increased when treated with CCl(4). Carnosine at 10 and 20 mM reduced SCE frequency in the human lymphocyte (p < 0.001). In addition, CCl(4) treatment significantly depleted the level of GSH, reduced the activity of SOD and GPx and elevated the level of MDA (p < 0.001). Carnosine treatment led to significant attenuation of CCl(4)-induced oxidative stress by normalization of the activities of SOD and GPx and the level of GSH and MDA (p < 0.05 or 0.001). These results suggest that carnosine could provide anti-oxidative and anti-genotoxic protection for the oxidative and genotoxic agents that cause many diseases including cancer and neurodegenerative disease.