Standard medical treatment for patients with acute venous thrombosis is antithrombotic therapy. Following a historical overview of the evolution of heparin therapy to include low-molecular weight heparin (LMWH), the pharmacokinetic properties of enoxaparin are described. Therapeutic advantages of LMWH over unfractionated heparin (UFH) are also discussed, including once- or twice-daily subcutaneous dosing, reduced hospital stays, elimination of therapeutic monitoring for most patients, and possibly less bone density loss. Studies have demonstrated that enoxaparin is at least equivalent to UFH with regard to efficacy and safety. Opportunities for future study include evaluation of enoxaparin's efficacy for the prevention of deep vein thrombosis within high-risk groups and for the treatment of thrombosis in such conditions as pregnancy, cancer, obesity, and renal insufficiency, and in children.