In order to evaluate their possible subacute toxicity, groups of 40 male and female ICR mice were given to the diet with chickens irradiated up to 30 kGy for four weeks. During the experimental periods, appearance, behavior, mortality, food and water consumption of mice fed irradiated chickens were not affected compared to the control. In urine analysis, hematological as well as in serum biochemical findings, no significant differences were found between the control (non-irradiated) and the irradiated chickens. Although minor changes in biochemical parameters were observed, they were in the normal range and were not dose dependent. Spotty necrosis was found in the male liver administered with 30 kGy irradiated chicken. However, it seems not related with gamma irradiation, because it lacks either the dose dependency and the secondary changes accompanied. Our results indicate that the adverse effect of gamma irradiated chicken can be observed at more than 30 kGy level.