The sensitivity of different larval stage duration pupae of Mediterranean fruit-fly, Ceratitis capitata to gamma irradiation, was tested by exposing pupae, 1 day before adult eclosion, to various gamma ray doses (60, 80 and 100 Gy). The treated pupae were biologically different in their larval span (5, 7 and 9 days). The pupae of med-fly having shorter larval period (5 days) were more resistant to sterilizing effects of gamma irradiation than those having longer larval period (9 days). The longevity of sterilized females developing from irradiated pupae, which had 5-and 7-day larval span, was increased considerably. Treatment of pupae which had 5-day larval span with a dose of 80 Gy, resulted in females which lived 84.3 days, but laid only 2.33 eggs as compared with their control females which lived 51.4 days and laid 976.71 eggs. In general, irradiation of pupae of different larval stage duration with a dose of 60 Gy or greater did not adversely affect the longevity of emerging adults. It is concluded that 60 Gy-irradiation of pupae having long larval span (9 days) should be used in the sterile insect release method for population suppression of Ceratitis capitata.