Functional endoscopic sinus surgery (FESS) is a commonly performed procedure for the treatment of chronic rhinosinusitis. It is most commonly performed as an outpatient procedure. Complications occur, including injury to the orbits, brain, and bleeding. Intraoperative injury to the internal carotid artery is rare and feared by otolaryngologists and skull base surgeons. Controlling this bleed is difficult and could be fatal. We report a case of intraoperative bleed of an internal carotid artery aneurysm during endoscopic sinus surgery. This case demonstrates that multidisciplinary coordination and prompt management can lead to a favorable outcome.