Acetone absorption in irradiated polycarbonate was investigated. The molecular weight and glass transition temperature of polycarbonate decreased with increasing the gamma-ray dose. Experimental data obtained from acetone transport in polycarbonate with various doses correlated sufficiently well with Karmon’s model which was accounted for case I, case II, and anomalous transport. The diffusion coefficient for case I, velocity for case II, and diffusion coefficient for diffusion front satisfied the Arrhenius plot for all gamma-ray doses. The equilibrium solubility satisfied the van’t Hoff plot regardless of the gamma-ray dose. Additionally, in the low-temperature range activation energies of case I, case II and the diffusion front, and the heat of mixing were found to have the same value for doses greater than 100 kGy which was different from those for unirradiated polycarbonate. This observation implied that acetone transport in irradiated polycarbonate occurs via the same mechanism for doses greater than 1000 kGy. The equilibrium solubility and diffusion coefficient for diffusion front at a given temperature were the same for all doses in the high-temperature range.