We compared the frequencies and types of infections that occurred in 448 patients with rheumatoid arthritis (RA) versus those occurring in 185 control patients who had osteoarthritis or soft tissue rheumatism. At least 1 infection developed in 23% of the RA patients and in 27% of the control patients. Using a series of risk factors, we found no substantial difference in the risk of infection in RA patients compared with that in control patients. Some of these factors, such as being female, having poor functional capacity, and receiving glucocorticoid treatment, were associated with different levels of risk for infection, but the levels were similar in RA patients and control patients.