Thrombotic risk should always be assessed in the various clinical scenarios of patients with cancer. Thromboprophylaxis with low-molecular-weight heparin is recommended above other anticoagulants for most patients with cancer who are hospitalised. However, the safety of primary thromboprophylaxis in this context is unknown; however, thromboprophylaxis can be completed with mechanical methods. Thromboprophylaxis in outpatients who are treated with chemotherapy is not indicated, except for outpatients who have other factors that determine a high thrombotic risk. In these cases, prophylaxis such as apixaban, rivaroxaban and low-molecular-weight heparin may be employed, provided there are no significant risk factors for bleeding or drug interactions. In patients undergoing oncologic surgery, thromboprophylaxis should be started before the surgery, continuing for at least 7 to 10 days and, in cases of major surgery, even up to 4 weeks. Drug prophylaxis is not routinely recommended to prevent upper extremity thrombosis in patients who carry central venous catheters.