this work investigated the effects of different packaging methods (air and vacuum) combined with irradiation (0.0, 2.0 and 3.0 kgy) on the preservation of chicken breast fillets stored at 1oc for up to 18 days by sensorial test, determination of ph and bacterial growth. the findings indicated that the post-irradiation lag phase increased with the dose, leading to an extension in shelf-life. vacuum-packed samples irradiated at 3.0 kgy exhibited the longest shelf life. among the analyzed bacteria, coliforms and listeria spp. were most sensitive to gamma radiation. all the fillets acquired more attractive coloration and better overall impression with irradiation. the combined use of vacuum packaging and irradiation (3.0 kgy) reduced the microbial populations without causing change in ph and yielded a significant shelf-life extension of refrigerated fillets, besides improving its appearance.