Background:Non-vitamin K antagonist oral anticoagulants (NOAC) have been developed as alternatives to warfarin. Until recently, the latter was the standard oral anticoagulant for patients with non-valvular atrial fibrillation (NVAF). The efficacy and safety of NOAC in Japanese patients with NVAF has been investigated in small trials or subgroups from global randomized control trials (RCT).Methods and Results:We conducted a systematic review and meta-analysis of RCT, to compare the efficacy and safety of NOAC to those of warfarin in Japanese patients with NVAF. Published research was systematically searched for RCT that compared NOAC to warfarin in Japanese patients with NVAF. Random-effects models were used to pool efficacy and safety data across RCT. Three studies, involving 1,940 patients, were identified. Patients randomized to NOAC had a decreased risk for stroke and systemic thromboembolism (relative risk [RR], 0.45; 95% CI: 0.24–0.85), with a non-significant trend for lower major bleeding (RR, 0.66; 95% CI: 0.29–1.47), intracranial bleeding (RR, 0.46; 95% CI: 0.18–1.16) and gastrointestinal bleeding (RR, 0.52; 95% CI: 0.25–1.08).Conclusions:NOAC are more efficacious than warfarin for the prevention of stroke and systemic embolism in Japanese patients with NVAF. The present findings offer clinicians a more comprehensive picture of NOAC as a therapeutic option to reduce the risk of stroke in Japanese NVAF patients. (Circ J 2015; 79: 339–345)