OBJECTIVES:  To perform a systematic review to evaluate the quality of anticoagulation control in outpatient pharmacist-managed anticoagulation services (PMAS) compared to routine medical care (RMC) METHODS: We searched MEDLINE, SCOPUS, EMBASE, IPA, CINAHL, Cochrane CENTRAL, with language restriction to English. Two authors independently reviewed each study and extracted data for all outcomes using a standardized form, with any disagreement resolved by a third author. The primary outcome was the quality of warfarin-related anticoagulation management using time in therapeutic range (TTR) as an indicator. Warfarin-related bleeding, thrombotic events and resource utilization were assessed as secondary outcomes. RESULTS: Of 155 articles identified, 23 articles met the criteria for final review. Of these, three studies were RCTs and twenty were observational studies. Most studies were conducted between year 2000 to 2013 (N=18, 78%), and study follow-up ranged from six to twelve months (N=13, 57%). Among studies that reported patients’ age, the average age ranged from 46 to 80.5 years, and was similar between PMAS and RMC groups. The majority of patients were treated for atrial fibrillation and venous thrombosis. Quality of anticoagulation control was better in the PMAS group compared to RMC, as indicated by higher TTRs in the majority of the studies (N=21, 91%). Clinical outcomes were also favorable in the PMAS group as evidenced by lower risk of major bleeding (N=10 of 14, 71%) or thromboembolic events (N=9 of 12, 75 %). This may contribute to improved healthcare utilization, as measured by the lower rates of hospitalization or emergency department visits (N=7, 78%). PMAS also resulted in cost-savings in seven of the studies. CONCLUSIONS: Pharmacist-lead outpatient anticoagulation services attained better quality of anticoagulation control, lower bleeding and thromboembolic events, and lower health care utilization.