The effect of electron-beam irradiation on microbial counts, color, texture, and enzyme activity of mushroom slices was evaluated at dose levels of 0.5, 1, 3.1, and 5.2-kGy. Irradiation levels above 0.5 kGy reduced total plate counts, yeast and mold, and psychrotrophic counts to below detectable levels and prevented microbial-induced browning. Firmness of all samples was similar during storage except for the 5.2-kGy sample. Color was preserved by irradiation as evidenced by the higher L* values. Electron-beam irradiation at these levels did not affect the polyphenol oxidase activity. Irradiation at 1 kGy was most effective in extending shelf-life of mushroom slices.