Surgical treatment of atrial fibrillation (AF) evolves to less invasive, safer and technically easier procedures mostly due to the electrophysiological studies, technological progress and creativeness in ablation systems construction. We present first clinical experience, mid- and long-term results of AF treatment with new liquid nitrogen cryothermy device for endocardial application. In 26 patients we have proved the feasibility and clinical effectiveness of liquid nitrogen cryocatheter ablation reaching more than 70% of sinus rhythm rate in long follow-up from 3 up to 24 months.