The aim of the study is to examine the comparative effectiveness of unfractionated heparin 5000 units given subcutaneously two or three times daily and enoxaparin given 30 mg subcutaneously twice daily or 40 mg daily for the prevention of venous thromboembolism in burn patients. This is a retrospective cohort study conducted in adult burn patients admitted between January 1, 1998, and September 30, 2008, who received only one agent for prophylaxis against venous thromboembolism during their admission. The primary outcome was a symptomatic venous thromboembolism, defined as any lower extremity deep venous thrombosis or pulmonary embolism. A total of 1111 patients were included; 600 received heparin and 511 received enoxaparin. Five patients (0.45%) experienced a symptomatic venous thromboembolic event. All five events occurred in the heparin group (P = .07). Heparin patients were older, had a larger TBSA burned, and a longer length of stay. No incidences of heparin-induced thrombocytopenia were identified. In this retrospective study of burned patients, the authors report a low incidence of symptomatic venous thromboembolic events. All events occurred in patients receiving unfractionated heparin as prophylaxis; however, the number of risk factors for venous thromboembolism was also greater in this group. Future prospective studies are needed to determine definitive conclusions regarding appropriate chemical VTE prophylaxis and dosing regimens for burn patients.