The 2 variations of the new criteria for rheumatoid arthritis (RA) proposed by a subcommittee of the American College of Rheumatology (ACR) in 1987 were evaluated and compared with the earlier (1958) criteria in 2 patients data collections from a Dutch rheumatological outpatient clinic. One group comprised 1,570 newly referred, consecutive patients, including 93 patients with RA. The other consisted of 1,338 patients with a clinical diagnosis of RA, whose charts were reviewed retrospectively. The sensitivities of the 2 variations of the 1987 criteria in the prospective and retrospective subgroups varied from 66 to 89%; those of the 1958 set, from 71 to 86%. Specificity was 98% for both criteria sets. Comparison in subgroups with different disease durations showed reduction in sensitivity for early RA for either variation of the new criteria. However, the differences between the results of the 1958 and 1987 criteria sets are small enough to conclude that they perform equally well.