The degree of concordance between clinicians' and patients' assessment of the patient's physical and mental functioning was examined in 166 consecutive eligible outpatients with rheumatoid arthritis (RA) using 4-category ordinal scales. The weighted kappa statistic was 0.39 for physical functioning and 0.30 for mental functioning, both indicating a fair degree of concordance. This disagreement differed in magnitude and direction depending on the level of disability present. We conclude that clinicians and their patients with RA often disagree in their assessment of the degree of physical and mental impairment that the patient experiences. These disagreements demonstrate the need for formal assessments of outcome and should be recognized and resolved when managing individual patients.