One hundred patients with classical (52) or definite (48) rheumatoid arthritis (RA) at one year after onset were followed up for 25 years. By then 63 had died, in one third of whom RA had either directly caused or contributed to death. These patients, at one year after onset of arthritis, had a higher proportion with classical RA and more functional impairment than the rest. Thirty five of the surviving 37 patients were seen for review. Eleven were well with no functional impairment. At one year after onset they had a lower erythrocyte sedimentation rate (ESR) and higher haemoglobin than the others, in whom a poorer outcome was associated with a persistently raised ESR and lower haemoglobin. The initial Rose-Waaler titre was a poor prognostic guide, but a better functional outcome was associated with conversion to seronegativity or a marked fall in rheumatoid factor level.