Aim. To study the possibility of using algorithms (developed using resting ECG as a mapping tool) for localization arrhythmogenic focus of ventricular arrhythmias (VA) detected by ambulatory 12-lead ECG monitoring (AECGM) with the identification of predominant origins of VA.Material and methods. The study included 54 patients aged 45 to 80 years with high frequency VA evaluated during AECGM: 29 — with coronary artery disease (CAD), 25 — w ithout CAD, who underwent radiofrequency ablation (RFA). The study included patients with effective ablation based on AECGM performed 6 months after RFA. Verification localization of VA exit site was carried out during endocardial mapping and AECGM («Cardiotechnika-04, СT-07», «Incart»). The following algorithms were considered in the study: D. Kuchar; O. Segal; J. Miller; A. S. Revishvili, R. Y. Snegur (2006, 2007); A. B. Weinstein; M. V. Noskova. It was assessed the percentage of matches applying the comparative analysis of results of the invasive and non-invasive methods, and it was revealed the predominant localization of VA.Results. The following algorithms had the highest percentage of matches: D. Kuchar in patients with CAD; A. S. Revishvili, R. Y. Snegur (2007) and M. V. Noskova in patients without CAD. The predominant origins of VA in patients without CAD were the left sinus of Valsalva, right ventricular outflow tract, and in patients with CAD — b asal inferior left ventricular wall, right ventricular outflow tract.Conclusion. Algorithms for arrhythmogenic focus localization of VA, developed using resting ECG, can be used to determine the origin of VA detecting by 12-lead AECGM, taking into account patient’s medical history (CAD, myocardial infarction).