This study focuses on determining the bioburden of oxygen masks manufactured by three different companies and dose optimization of gamma radiation for the elimination of the bioburden. The bioburden was identified by performing morphological analysis through gram staining and biochemical characterization by API 20E strip. The results confirmed the presence of three different types of bacteria: Bacillus subtilis, Staphylococcus epidermidis and Staphylococcus aureus. The oxygen masks showing maximum bioburden were sent to Pakistan Radiation Services (PARAS) for irradiation at three different selected doses 20 kGy, 25 kGy and 30 kGy. Although 25 kGy was recommended for the sterilization of disposable medical devices but in this case effective and complete elimination of the bioburden was achieved at the dose of 30 kGy. Improperly sterilized oxygen masks are responsible for causing secondary infection among immunocompromised patients, thus sterilized oxygen masks through optimized gamma radiation help in raising the standard of public health by preventing the risk of infections.