The effects of gamma irradiation on a mixture of aflatoxins B1, B2, G1, G2 were studied. Standard solutions of A and B were irradiated at 5, 10, and 20 kGy in a solution of water/DMSO (9 + 1, v/v) by using a 137Cs source. The control (0 kGy) and irradiated samples were subjected to RP-HPLC analyses with methanol/water (4 + 5, v/v) as the mobile phase. Aflatoxin B1 (AFB1) was the most radio-sensitive of the four compounds. The radiosensitivity of the other aflatoxins, was in increasing order: G2, B2, G1. Only about 5% of AFB1 remained after irradiation of solution A at 5 kGy. When the concentration of solution B was increased two-fold, trace amounts of AFB1 remained after irradiation doses of 10 and 20 kGy. Irradiation was found to be suitable for the destruction of aflatoxins in solution.