Because there is little information about the efficacy of home occupational therapy, we decided to assess the effects of a home service on patients with rheumatoid arthritis. 105 patients aged 18-70 years, on stable medical therapy, were randomised to receive a 6-week comprehensive programme of occupational therapy (experimental group, 53 patients) or to receive no such treatment (control group, 52). At 6 weeks, control patients received the experimental regimen, and experimental patients were continued on treatment as needed up to 12 weeks. Outcomes were measured at baseline, 6, and 12 weeks with a global functional capacity score (functional score). At 6 weeks the functional score for the experimental group was significantly higher than that for the control group (mean difference = 8.1, 95% Cl 1.7 to 15.8, p = 0.012). Control patients at 12 weeks showed a similar improvement to experimental patients at 6 weeks, and between 6 and 12 weeks the experimental patients were stable. Occupational therapy leads to a statistically significant and clinically important improvement in function in patients with rheumatoid arthritis.