Drainage bags are used in patients that have urinary retention or having surgery. Many infectious diseases have been reported due to the use of unsterilized catheters of these drainage bags. The undertaken provides the most efficient method for sterilization of drainage bags that is gamma radiations. The dose of 25kGy was optimized at which no microbial load were found. So, it was concluded that gamma radiations are very effective method for sterilization of drainage bags