To evaluate mortality and causes of death in patients with rheumatoid arthritis (RA) treated with low-dose oral glucocorticoids. Mortality was analyzed in population-based data of 604 patients with RA. In the original study in 1988, state of general health, severity of RA, and treatment including the use of oral glucocorticoids were recorded. In 1999 vital status and causes of death were evaluated. Mortality in patients with RA who had not received glucocorticoids (Group A, n = 209) was compared to that in patients treated with glucocorticoids for less than 10 years (Group B, n = 276) or for more than 10 years (Group C, n = 119). From onset of RA to 1999, 395 (65%) patients had been treated with oral glucocorticoids. In 1999 a total of 160 (26%) patients had died, 23% of patients in Group A, 21% in Group B, and 45% in Group C. In multivariate Cox regression analysis, male sex (hazard ratio 2.50; 95% CI 1.74-3.59), impaired functional capacity by Health Assessment Questionnaire (HR 2.11; 95% CI 1.65-2.96), heart failure (HR 1.96; 95% CI 1.36-2.84), and diabetes (HR 1.87; 95% CI 1.17-3.01) predicted increased mortality. In the same analysis glucocorticoid treatment for 1 year increased the mortality risk by 14% (HR 1.14; 95% CI 0.98-1.27, p = 0.057) and treatment over 10 years by 69% (HR 1.69; 95% CI 1.12-2.56, p = 0.011) compared to RA patients without treatment. The major cause of death was cardiovascular disease in all groups, but infections and intestinal perforations due to amyloidosis were more frequent in patients with long-lasting glucocorticoid therapy. Lymphomas were more frequent in all patients treated with glucocorticoids (Groups B and C) than in those not receiving glucocorticoids. Patients with RA treated with low-dose oral glucocorticoids for more than 10 years had increased mortality compared to those who did not receive glucocorticoids or whose duration of treatment was less than 10 years. The increased mortality was related mainly to infections and complications caused by systemic amyloidosis.