Venous thromboembolism (VTE) is a common complication in patients with malignant disease. Cancer-associated thrombosis is a major cause of morbidity and mortality in patients with cancer. Several risk factors for developing venous thrombosis usually coexist in cancer patients including surgery, hospital admissions and immobilization, the presence of an indwelling central catheter, chemotherapy. Effective prophylaxis and treatment of VTE reduced morbidity and mortality, and improved quality of life. Low-molecular-weight heparin (LMWH) is preferred as an effective and safe means for prophylaxis and treatment of VTE.