Patients treated with a vitamin K antagonist may require interruption of their anticoagulation prior to an invasive procedure or surgery, and as a result, may be placed at a higher risk for thromboembolic events during this time. Either low-molecular-weight heparin (LMWH) or unfractionated heparin is frequently used to bridge the gap in anticoagulation treatment because of their relatively rapid onset and offset of action compared to warfarin. Despite the lack of randomized trials supporting the efficacy of this bridging therapy, guidelines have been developed to assist providers with this common clinical challenge. Key issues in bridging therapy include identifying patients who can safely undergo an invasive procedure while continuing their vitamin K antagonist, identifying those who will likely gain the most benefit from bridging anticoagulation, and determining the optimal dose and timing of parenteral anticoagulants in the perioperative period.