Purpose: To evaluate the clinical results of anteroinferior tibiofibular ligament avulsion fracture accompanied ankle fractures treated with anatomical reduction and internal fixation. Materials and Methods: From January 2007 to April 2010, 30 cases with anteroinferior tibiofibular ligament avulsion fracture that treated with anatomical reduction and internal fixation were analyzed. The average follow-up period was 26 months (minimum 6 months). We have reviewed the bony union, complication and subjective satisfaction according to the fracture classification and method of internal fixation. Results: Among 30 cases, 28 cases were occurred in Lauge-Hansen classification supination-external rotation type, one case was fracture-dislocation and one case was Maisonneuve fracture. We have performed internal fixation with Mini screw in 11 cases, K-wire in 10 cases, repair in six cases and Mini screw & K-wire in three cases. In all cases bony union was completed. two cases in Mini screw, one case in K-wire, two cases in repair and one case in Mini screw & K-wire revealed LOM of ankle joint. Skin irritation and superficial peroneal nerve irritation happened in one case each. Other cases show good subjective satisfaction. Conclusion: Anteroinferior tibiofibular ligament avulsion fracture accompanied with ankle fracture is a good clinical outcome with internal fixation. So we should not miss out the anteroinferior tibiofibular ligament avulsion fracture in radiologic evaluation or operation room.