The prognosis 3 years after the onset of the disease was studied in 107 patients with definite rheumatoid arthritis, 161 with probable RA or non-specific arthritis, 84 with either ankylosing spondylitis, Reiter's disease or reactive arthritis, 14 with psoriatic arthritis and 10 with a systemic connective tissue disease. Prognosis was measured by clinical involvement of joints, radiological erosions in joints, deterioration in joint function, ESR, and working ability. A total of 44% of all patients were symptomless after 3 years. The prognosis was best in patients with an "HLA B 27-associated" disease and non-specific arthritis, and worst in RA. Two patients died during the follow-up of systemic connective tissue disease and one committed suicide with an overdose of hydroxychloroquine. Two HLA B27-positive patients developed systemic amyloidosis.