The influence of age at onset was studied in a prospective followup of early rheumatoid arthritis (RA). Patients greater than or equal to 60 years (n = 71) showed significantly more often an onset in both large and small joints and higher disease activity at the start compared with patients less than 60 years (n = 142). The higher disease activity was still present after 2 years of followup (greater than or equal to 60 years, n = 46, less than 60 years, n = 101); as well, there was a tendency towards more radiographic damage. Rheumatoid factor (RF) and DR4 were comparable in both age groups. Our data show a more severe course in older age RA. This disagreement with the literature is probably due to the fact that many studies are cross sectional with unbalance of RF in the 2 age groups.