Results of an observational study. devoted to prevention of thromboembolic complications in patients with atrial fibrillation undergoing catheter pulmonary vein atrium isolation are discussed. Patients (n= 199) were divided into two comparable groups depending on the anticoagulant (rivaroxaban or warfarin) used. Clinical thromboembolic and/or hemorrhagic complications as well as rate of development of asymptomatic cerebral thromboembolisms in various periods after procedure were assessed. Main conclusion: rivaroxaban was not inferior to warfarin for thromboprophylaxis in patients with atrial fibrillation undergoing catheter pulmonary vein antrum isolation.