The effects of low-dose (1 kGy) gamma radiation and selected phosphates on the microbiology of refrigerated, vacuum-packaged ground pork were studied. Low-dose gamma radiation reduced (P 0.05) pH differences between irradiated and nonirradiated treatments, and irradiation treatment did not significantly (P > 0.05) increase lipid oxidation. Lipid oxidation was also not affected by phosphates. Pseudomonas was the major bacterial genus constituting the nonirradiated refrigerated (5(DEGREES)C), vacuum-packaged ground pork microflora. Pseudomonas predominated in nonirradiated samples in four of five sampling times. There was a decrease in the incidence of Pseudomonas as storage time increased. Irradiation greatly decreased the numbers of gram-negative microorganisms, resulting in predominance of the gram-positive, nonsporeforming Lactobacillus and coryneform bacteria.