Exposure of viral pathogens to ionizing radiation can be an effective method of neutralization. Potential applications include decontaminating materials and providing non‐infectious antigens for diagnostic and therapeutic applications. As radiation can completely penetrate through most biological and non‐biological materials, there can be high assurance that all the viruses have been completely exposed. This report will include recent experimental work investigating the radiation sensitivity of influenza A and vaccinia viruses, as well as a brief review of the published literature. Data to be presented includes the dose range for virus inactivation, comparisons of different types of ionizing radiation and putative molecular mechanisms. Biological and methodological parameters affecting radiation sensitivity and its measurement will also be discussed.