Pupae of Lobesia botrana (one day before eclosion) were irradiated with 10, 15, 20, 25, 30, 35 and 40 krad. Combinations of irradiated males x normal females, normal males x irradiated females and normal males x normal females were tested. The results showed that sterility of males were obtained to some extent at the different dosages of gamma radiation. Males were completely sterile at 40 krad. In general, as the irradiation dose increased, egg hatchability decreased. The data indicated that there was a significant effect of radiation on fecundity of females compared with that of control. At 40 krad, the reduction of eggs laid by female reached 86.86%, as the irradiation dose increased the number of deposited eggs by female decreased and consequently the reduction increased. Hatchability of eggs laid by irradiated female was 0.00 at 25-40 krad. In general, females were more sensitive to radiation than males. Also, the same results clarified that the irradiation of pupae of L. botrana reduced the longevity of emerged 'males and females. Longevity of emerged males signifiacantly decreased to 8.30 days at 40 krad compared with 17.30 days for untreated ones. Female longevity, that insignificantly affected with radiation, was 18.30 days when received 40 krad. The longevity of untreated females was 22.50 days.