Cardiac arrest is the most serious problem during anesthesia and surgery. Whether the heart is in ventricular fibrillation, in asystole or in EMD, the ABCDS of CPR must always be used. The authors have experience with cardiac arrest obviously due to the complexities of vagovagal reflexs and severe electrolyte imbalance, especially in potassium ions. After the diagnosis of ventricular fibrillation in our case by continuous ECG monitoring, immediate closed chest cardiac massage was carried out and the essential drugs and a DC defibrillator were used. At the first attempt, the normal sinus rhythm was restored immediately after 100 joules of DC countershock were given. We then gave another 200 J. of a second shock for recurrent VF. Thereafter, complete normal sinus rhythm was restored without dysrhythm of any kind. Simultaneously the authors also several times observed changes of arterial blood gases and pH. About ten hours later the patient regaineded consciousness completely without complications. If possible, continuous ECG monitoring during anesthesia is highly recommended because various dysrhythmias can be detected by this system.