We attempted to determine what baseline variables are responsible for the efficacy of tacrolimus at 6 months in Japanese patients with rheumatoid arthritis (RA). One hundred and six RA patients treated with tacrolimus for 6 months were entered in this study. The outcome was set as the achievement of Disease Activity Score 28 C-reactive protein (DAS28-CRP) remission at 6 months. We examined the association of gender, DAS28-CRP at baseline, concomitant use of methotrexate (MTX), and concomitant use of prednisolone with the achievement of DAS28-CRP remission at 6 months by logistic regression analysis. Twenty-three of 106 patients (21.7%) achieved DAS28-CRP remission at 6 months. There was concomitant use of MTX by 20 patients (18.9%), prednisolone by 93 (87.7%), and prednisolone [5 mg/day by 43 (40.6%) at baseline. Logistic regression analysis showed that male gender (first) and moderate disease activity at baseline (second) are independent predictors toward achieving DAS28-CRP remission at 6 months. Maximum tacrolimus dosage administrated for patients over a 6-month period appeared not to be predictive for the DAS28-CRP remission at 6 months. In conclusion, we revealed for the first time that good outcome in RA patients treated with tacrolimus can be predictive by some baseline variables. That is clinically valuable for daily practice in the choice of disease-modifying antirheumatic drugs (DMARDs), especially tacrolimus.