BACKGROUND Oral glucocorticoids are widely used to treat patients with rheumatoid arthritis, but their effect on joint destruction, as assessed radiologically, is uncertain. METHODS We conducted a randomized, double-blind trial comparing oral prednisolone (7.5 mg daily for two years) with placebo in 128 adults with active rheumatoid arthritis of less than two years' duration. Except for systemic corticosteroids, other treatments could be prescribed. The primary outcome variables were the progression of damage as seen on radiographs of the hand after one and two years, as measured by the Larsen index, and the appearance of erosions in hands that had no erosions at base line. The radiographs were viewed jointly by a radiologist and a rheumatologist who were unaware of the treatment assignment and the time point at which the films were obtained. RESULTS The statistical analysis of radiologically detected changes was based on 106 patients for whom there were films obtained at base line and two years later. After two years, the Larsen scores increased by a mean of 0.72 unit in the prednisolone group, indicating very little change, and by 5.37 units in the placebo group, indicating substantial joint destruction (P = 0.004). Of the 212 hands of these patients, 147 (69.3 percent) had no erosions at the start of the study. At two years, 15 of the 68 such hands in the prednisolone group (22.1 percent) and 36 of the 79 such hands in the placebo group (45.6 percent) had acquired erosions (difference, 23.5 percentage points; 95 percent confidence interval, 5.9 to 40.7; P = 0.007). The patients in the prednisolone group had greater reductions than the patients in the placebo group in scores on an articular index and for pain and disability at 3 months; for pain at 6 months; and for disability at 6, 12, and 15 months (all P < 0.05). There was no difference between groups in standardized scores for the acute-phase response. The adverse events were typical of those encountered with antirheumatoid drugs. CONCLUSIONS In patients with early, active rheumatoid arthritis, prednisolone (7.5 mg daily) given for two years in addition to other treatments substantially reduced the rate of radiologically detected progression of disease.