Twenty-nine temporomandibular joints (TMJs) in 19 patients with chronic arthritic disease were surgically treated. Nine patients had rheumatoid arthritis (including two with juvenile type), six had ankylosing spondylitis and four had psoriatic arthropathy. Using a preauricular approach, diskectomies with synovectomies were performed in 23 joints (14 patients) with chronic arthritic abnormalities. Diskectomies without synovectomies were performed in six joints (five patients), which proved to have internal derangements unrelated to their chronic arthritic disease. Joints with chronic arthritis showed considerable variation in inflammatory reactions, but were characterized by increased vascularization, synovial proliferation to the articulating surfaces and mostly pannus formation and bone resorption. A response in pain relief was seen in 85% of the patients three months postoperatively and in 79% of the patients 12 months postoperatively, indicating that diskectomy with synovectomy may be favorable in patients with severe TMJ problems due to involvement of chronic arthritic disease.