Background: The traditional method of seeing warfarin patients face-to-face and titrating their international normalized ratio (INR) in anticoagulation clinics has advanced over the years to include an alternative telephonic consultation with expanded collaborative services involving outpatient polyclinics and use of selftesting coagulometers. Objective/Setting: This study evaluated the clinical and safety outcomes of using telephonic vs face-to-face consultation in a pharmacist-led outpatient anticoagulation service at National University Hospital (NUH), a tertiary hospital in Singapore. Method: A retrospective observational study was carried out in patients with atrial fibrillation whose warfarin therapy was managed by either standard or telephonic anticoagulation services. Patients on at least 2 months of warfarin therapy prior to study inclusion were recruited from January to June 2017 and followed up for 6 months. Main Outcome Measure: Clinical outcomes included mean INR time in therapeutic range (TTR), INR TTR ± 0.2 units and ± 0.5 units variances, mid-point INR TTR, and patients with INR >5 within the 6-month study period. Safety outcomes included thromboembolic events, major bleeding, and clinically relevant nonmajor bleeding. Results: A total of 152 patients were included in the analysis. The mean TTRs (including the variances) were all not statistically significant between face-to-face and tele