The small molecule, arginomimetic drug argatroban is the first synthetic direct antithrombin to be approved for clinical use. Argatroban reversibly binds to and inhibits both soluble and clot-bound thrombin. In contrast to other direct thrombin inhibitors, argatroban upregulates nitric oxide, enhancing its antithrombotic effect, does not generate antibodies, is not susceptible to degradation by proteases and is hepatically cleared. It has a predictable anticoagulant effect. Argatroban has proven efficacy and safety for prophylaxis and treatment of patients with thrombosis associated with heparin-induced thrombocytopenia (HIT), and for percutaneous coronary intervention in HIT and non-HIT patients. Pilot studies suggest that further investigations to establish the use of argatroban in ischemic stroke, acute coronary syndrome, hemodialysis, blood oxygenation, off-pump cardiac surgery and other clinical indications are warranted.