The early suppression of disease activity during the first 2 years in rheumatoid arthritis (RA) has been reported to be exclusively important to prevent joint destruction and functional decline. Since single disease-modifying antirheumatic drugs(DMARDs) therapy is still disappointing, many rheumatologists today advocated a more aggressive approach using combinations of classic DMARDs. Many clinical trials on combination therapy have been reported and most studies of combination therapy focused on the efficacy of a treatment strategy. Therefore, the possible synergistic action of combination of drugs has not been demonstrated. Among combination of therapy of classical DMARDs, only few trials demonstrated the efficacy of combination therapy. The incidence of adverse effects among 341 RA patients was investigated by our department. The incidence of adverse effect in combination therapy revealed 36.4% which was not statistically different from that in monotherapy(33.6%, p = 0.41). The recent studies on combination therapy on classical DMARDs are not encouraging, however, the combination therapy for patients with early RA, drugs utilizing immunosuppressant, biologics and other newly developed drugs will still have a chance to expect a potent efficacy for RA.