The efficacy of temporomandibular joint diskectomy without implants was evaluated clinically in patients with internal derangements. Seventy-two patients were examined preoperatively and 1 year postoperatively; 40 were also examined 3 years postoperatively and 15 at 5 years after surgery. Success rates were calculated according to a modification of the criteria established in 1984 by the American Association of Oral and Maxillofacial Surgery. The success rate was 83% at the 1-year follow-up. Temporomandibular joint pain was alleviated and chewing capacity was normalized in 60 patients. The outcome in 12 patients was classified as unsuccessful, mainly on the basis of residual muscle and joint pain. At the 3-year follow-up only two patients were classified as unsuccessful and none at the 5-year follow-up. Unsuccessful patients had higher frequencies of muscle soreness and osteoarthrosis than successful patients. Postoperative complications were infrequent and minor.