The iatrogenic cause of bile duct stone formation is mainly due to suture materials, especially silk sutures. In recent years, Prolene and Vicryl sutures have been widely used in biliary surgery, and bile duct stone formation related to sutures are seemingly becoming rare, as there has only been one report of bile duct stone formation caused by Prolene sutures in the literature. In the last few years we have had two cases of Prolene suture-related bile duct stone formation within our unit. We therefore suggest that Vicryl sutures should be used as the first choice in biliary surgery, in order to prevent the formation of iatrogenic bile duct stones.