Pulse oximetry is a noninvasive, reusable device that is being used routinely in anesthesia procedure for monitoring oxygen saturation. This is a very beneficial device that can quickly detect of hypoxia, the most common cause of anesthesia-related death. However, in clinical uses, false desaturation readings are frequently found to be caused by various factors. Such as by the use of intraoperative blue dye, which can falsely decrease oxygen saturation as determined by pulse oximetry. We therefore report our findings concerning prolonged decreased pulse oximetry readings due to the intraoperative use of blue dye subcutaneously.