Total bacterial numbers were reduced three to four log cycles upon exposure of shell stock oysters to ionising radiation (60Co) at 1.0, 2.0 and 5.0 kiloGrays.Vibrio vulnificus was detected in the non-irradiated control shell stock oysters, however, it was not detected in any of the shell stock after 1.0, 2.0 and 5.0 kiloGrays of exposure. The shelflife of irradiated shell stock oysters and depurated oysters was also compared. Fifty percent of the irradiated oysters were dead within 12, 10 and 7 days at 1.0, 2.0 and 5.0 kiloGrays of exposure, respectively. In contrast, fifty percent of the depurated oysters were dead after 31 days. Cultures of virulent and avirulent Vibrio vulnificus in phosphate buffered saline were quite radiosensitive as no colony forming units could be detected after 0.5 kilogray exposure.