Objective: To evaluate the effect of arthroplasty using interpositional cartilage allografts in patients with temporomandibular joint (TMJ) arthrosis. Study Design: This retrospective study included patients treated consecutively between 2007 and 2013 using discectomy and interpositional grafting with lyophilized costal cartilage allograft (Tutoplast) sheets. TMJ pain based on the visual analogue scale (VAS), maximal interincisal opening (MIO), joint tenderness to palpation, crepitus from the affected joint, and postoperative complications were assessed. Results: Arthroplasty was performed on 37 joints among 34 patients (28 women; mean age: 54 years); 24 joints underwent simultaneous condyle shaving. At final follow-up (3 [n = 37] or 5 [n = 21] years), we observed reduced mean VAS (from 7.6 to 0.9; P < .001) increased mean MIO (from 32.5 to 41.1 mm; P < .001), number of joints with capsule tenderness (from 30 to 3; P < .001), and percentage of joints with crepitus (from 97% to 75%; P = .008). One joint required reoperation because of interposed cartilage fragmentation. No permanent facial nerve injury or malocclusion occurred after treatment. Conclusions: Interpositional arthroplasty is a relatively simple, moderately invasive, and effective surgical treatment for TMJ arthrosis with few complications. However, long-term outcomes of this treatment, specifically beyond 3-5 years postoperatively, remain unknown.