Purpose: We propose a new classification of subcondylar fractures of the mandible based on ramal height shortening and degree of fracture angulation and present our treatment experience using this classification system. Patients and Methods: Eighty patients with subcondylar fractures of the mandible were evaluated. We categorized the fractures into 3 classes: Class 1 (minimally displaced), fracture with ramal height shortening: <2 mm and/or degree of fracture displacement: <10 degrees; Class 2 (moderately displaced), fracture with ramal height shortening: 2 to 15 mm and/or degree of fracture displacement: 10 to 35 degrees; Class 3 (severely displaced), fracture with ramal height shortening: >15 mm and/or degree of fracture displacement: >35 degrees. Our treatment protocol is closed treatment for Class 1 fractures; either closed or open treatment for Class 2 fractures; and open treatment for Class 3 fractures. Results: Among 80 patients, 20 had Class 1 fractures (25%), 40 had Class 2 fractures (50%), and 20 had Class 3 fractures (25%). In Class 2 fractures, 22 patients were managed by closed treatment (Class 2a) and 18 by open treatment (Class 2b). No statistically significant differences were found between the 3 classes in terms of functional outcome, while, within Class 2 patients, significantly (P = .00) better functional results were observed in open (Class 2b) group compared with closed group (Class 2a). Conclusions: Our new classification based on ramal height shortening and degree of fracture displacement can better guide clinical treatment. Class 1 fractures are treated by closed method, while open reduction is recommended in Class 2 and Class 3 cases. (C) 2011 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 69:1159-1165, 2011