The joints of hands and feet of 25 patients (1150 joints) with rheumatoid arthritis were compared, joint by joint, clinically and radiologically, over 2 years of treatment with remission-inducing drugs. Joints with clinical signs of synovitis decreased from 47% to 17% (p less than 0.001), while the number of joints with radiological lesions increased from 23% to 27% (p less than 0.01). Definite radiological progression of bone lesions was seen in 7% of the joints. Joints with clinical synovitis had a higher risk of progressive bone damage than joints without clinical synovitis (p less than 0.001) and joints in which the clinical signs of synovitis persisted during the study had a higher risk of progressing bone lesions than joints in which the clinical synovitis subsided (p less than 0.001). Progressive bone damage was seen more often in swollen joints than in tender joints without swelling or joints without clinical signs of synovitis (p less than 0.001), the difference in radiological progression between the latter two groups being non-significant. Twenty-one per cent of the joints with progressive bone lesions had no clinical signs of synovitis during the period.