Cardiac tamponade can result in severe hemodymanic instability, including cardiac arrest. We experienced one case of unexpected cardiac tamponade during permanent pacemaker insertion using da VinciTM Surgical System (Intuitive Surgical Inc., Mountain View, USA) in 76-year-old male patient with complete atrioventricular block. Soon after the port insertion for robotic arm, sudden-onset electromechanical dissociation was developed. Prompt cardiopulmonary resuscitation was performed. Rapid left thoracotomy revealed the cardiac tamponade caused by the injury of right ventricle. Hemodynamic parameter was immediately improved after pericardiocentesis and primary repair of right ventricle. Permanent pacemaker was inserted uneventfully through the left thoracotomy. The patient was discharged 10 days after operation without any other complication.