Thrombosis is a common complication in patients with cancer. Low molecular weight heparins have been shown to be effective in both the prevention and treatment of venous thromboembolism in the cancer patient. More recently, studies have confirmed the benefits of extended duration of LMWH in the primary prevention of VTE after cancer surgery and for up to six months therapy for acute symptomatic VTE treatment. Beyond these well established uses for LMWH in the prevention and treatment of thrombosis in cancer patients, contemporary studies have demonstrated that LMWH therapy can prolong survival in patients with solid tumour malignant disease.