Bucillamine (Buc), developed in Japan, is a disease-modifying antirheumatic drug (DMARD) which has been used to treat numerous patients with rheumatoid arthritis (RA) in Japan and Korea with favorable results. However, it has not been used globally. In the present study, we compared the timing of onset of efficacy and the usefulness of this drug with that of the globally accepted agent salazosulfapyridine (SASP). There were 26 patients in the Buc group and 23 in the SASP group. We compared changes in the number of swollen joints, number of painful joints, duration of morning stiffness, grip strength, levels of inflammatory marker [erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)], rheumatoid factor (RF), physician's rating by visual analogue scale (VAS), patient's rating of pain, patient's overall rating (VAS), and improvement according to European League against Rheumatism (EULAR) criteria (DAS28-CRP, DAS28-ESR) in these two groups of patients. Both Buc and SASP were shown to be efficacious within 3 months after the start of treatment. Both drugs were found to be suitable as first-line treatment of early RA. Signs of efficacy tended to occur earlier with Buc than with SASP, and Buc also tended to have higher efficacy than SASP.