The indwelling percutaneous radial artery catheter is used worldwide especially during major operations or with critical patients in the intensive care units. Complications that occur following radial artery puncture for continuous blood pressure monitoring and frequent arterial blood gas determinations include vascular insufficiency, bleeding, and infection. Most of these complications can be managed conservatively, without deficit. We report a rare complication, a mycotic pseudoaneurysm, occurring after arterial catheterization, which necessitated radial arterial ligation and skin grafting.