This study was carried out to evaluate the genotoxicity of the gamma-irradiated (0, 5 and 10 kGy) milk and ice cream. The Salmonella typhimurium reversion assay was performed using S. typhimurium TA98, TA100, TA102, TA1535 and TA1537 as tester strains. The number of revertant colonies were not increased in both milk and ice cream, compared with negative controls with or without metabolic activation. There were no significant differences among the irradiation doses. These results indicate that the gamma-irradiated milk and ice cream do not show any genotoxic effect under these experimental conditions, and that they may be safe genotoxically.