Internal carotid artery (ICA) injury during transsphenoidal surgery is a rare but serious complication. We analyzed a series of ICA injuries that occurred during a transsphenoidal approach to suggest an optimal management strategy. Between January 2015 and May 2020, we enrolled 10 cases of ICA injury at our institution. Among the 10 patients enrolled, 5 had pituitary adenoma, 2 had craniopharyngioma, and 1 each had skull base chondrosarcoma, tuberculum sellae meningioma, and nasopharyngeal cancer; 4 were revision surgery cases. The cavernous segment of the ICA was the most commonly injured area. The most common reason for ICA injury was a drill injury at the sellar floor opening. A direct repair was performed using a clip in only 1 patient. In the others, bleeding control of the injured ICA was achieved by packing multiple cotton pads. After angiography, 6 patients underwent immediate endovascular sacrifice of the injured ICA. In 3 patients who showed poor collateral flow from the anterior communicating and posterior communicating arteries, revascularization surgery was performed before endovascular trapping. After 6 postoperative months, 6 patients showed favorable functional outcomes, and 4 patients showed poor functional outcomes. Prompt control of bleeding, endovascular management of injured ICA, and consideration of revascularization surgery based on collateral flow may prevent catastrophic neurological sequelae.