Central to the question of anesthetic risk is the definition of an anesthetic death. This is yet to be defined within any reasonable limits. A number of factusl and philosophical considerations complicate attempts to derive a precise definition. Since anesthesia is usually administered only to permit or facilitate a diagnostic or therapeutic procedure, anesthesia risk is largely confounded with surgical risk and a second set of persons and procedures. For most death, assignment of the relative roles of anesthesia, surgery and patient disease is based on retrospective assumptions, hindsight judgment, bias, and incomplete information. We would like to make a plea for a more widespread use of death reports and more detailed discussion of fatalities occurring in patients who have received anesthesia. Therefore, we have evaluated cardiac arrest during peri-anesthesia this ten-year period (1969~1979) in St. Mary's hospital: 28, 124 anesthetics were administered. On the other hand, recently the developments that led, to widespread organization of hospital based cardiac resuscitation programs in the early sixties were direct mechanical ventilation of the lungs, external cardiac compression, external cardiac electrical defibrillation and conduct a intensive care unit. Obviously, the concept of anesthetic death must contain a judgment of the relative roles of error and toxicity, also. Evaluated results were as follows; 1) Incidence of cardiac arrest was 1: 55. 2) Forty six percent of cardiac arrest was encountered in the thirty to forty age group. 3) Increasing incidence of cardiae arrest was encountered in poor physical status. 4) Etiological factors in cardisc arrest were overdose of anesthetic drags, hypovolemia, electrolyte imbalance and a disease focus in the central nervous system. 5) Cardiac arrest due to the patient's disease itself was 47%, contributed surgical stress was 22% and contributed anesthetic stress was 31%. 6) Highest incidence of cardiac arrest was encountered in hepatobiliary tract diseases.