Direct oral anticoagulants (DOACs) may be used in the treatment of cancer patients. According to several tudies, they have an advantage over warfarin and are not less effective than low-molecular-weight heparin. The choice of medication should be individualized based on several factors, including the purpose of treatment, location of the tumour, the risk of bleeding, and potential drug interactions. Anticancer drugs that are potent inhibitors of CYP3A4 and/or P-gp increase DOACs` plasma concentrations, and potent inducers of CYP3A4 and/or P-gp decrease DOACs’ levels. However, mostly owing to the fact that DOACs have a wide therapeutic window, it can be assumed that many interactions need not manifest themselves clinically. Therefore, patient monitoring is necessary in these cases.