Self-monitoring of long-term oral anticoagulant therapy has been possible since 2002. Warfarin self-dosing, although an accepted practice by the American College of Chest Physicians, is seldom offered to patients. This quality improvement study involved implementing and evaluating patient engagement in self-management of warfarin (international normalized ratio self-testing and warfarin self-dosing). This practice was found to be as safe and effective as provider management and resulted in tighter control of variance of international normalized ratio. This intervention should be offered to eligible patients because it promotes engagement in behaviors that reduce the impact of their disease and decreases the burden of care on the provider.