The aim of the study was to establish predictors of atrial fibrillation (AF) relapse in 6 months after cardioversion in patients with persistent AF, based on clinical, anamnestic parameters, data of transtoracal and transesophageal echocardiography. The study included 122 patients with persistent non-valvular AF with planned restoration of sinus rhythm. After planned cardioversion sinus rhythm was restored in 114 patients (93.4 %), in 8 patients (6.6 %) cardioversion was not achieved. Among 114 patients with successful cardioversion sinus rhythm in 6 months was preserved in 74 (64.9 %), AF relapse in 6 months was registered in 40 (35.1 %) patients. The probability of AF relapse depended on age, stage of arterial hypertension, heart failure, diabetes mellitus, earlier stroke or transient ischemic attack, as well as on functional state of left atrial appendage, but not left atrial cavity. Preservation of sinus rhythm in 6 months was associated with improvement of structural and functional state of myocardium and central hemodynamics parameters.