In view of the high risk of venous thrombolism (VTE) in critically ill patients, it is essential for all ICUs to develop a standardized approach to thromboprophylaxis. Several studies in a critical setting have shown that both low dose unfractionated heparin and low molecular weight heparin (LMWH) reduce the incidence of VTE and either one of them is recommended as a valid agent by the newer ACCP consensus guidelines.