Thrombosis is a common complication in cancer. Patients with malignancy have a prothrombotic state due to the ability of almost all type of cancer cells to activate the coagulation system. Prothrombotic factors in malignancy include the tumor production of procoagulants as tissue factor (TF) and cancer procoagulant (CP). Clinical, laboratory, histopathological, and pharmacological evidence support the notion that tissue factor (TF), thrombin, and fibrinogen also affect cancer by the activation of angiogenesis, a process which is essential in tumor growth and metastasis by both clotting dependent and independent mechanisms.