Abstract: Cryoballoon ablation for paroxysmal atrial fibrillation (AF) has been recommended as a first-line treatment by 2016 ESC Guidelines for the management of atrial fibrillation and its effectiveness and safety has been previously demonstrated. Compared with radiofrequency ablation, cryoballoon ablation possesses the characteristics of briefer learning curve, shorter operation time, and less patient suffering. As a result, cryoballoon ablation is widely accepted in clinical treatment. However, phernic nerve paralysis, the most common complication, should be well understood to minimize occurence. In this review, we present a systematic investigation of phernic nerve paralysis caused by cryoballoon ablation for paroxysmal atrial fibrillation.