To evaluate whether the perioperative myocardiac infarction or cardiac mortality can be predicted in non-cardiac surgery, a computer program for the prediction value was applicated 70 normotensive and 93 hypertensive patients. The eight questions which are required a answer either "yes" or "no" for emergency surgery, experience of anginal attacks, ischemia on electrocardiography, history of myocardiac infarction, age over 70 years, laparotomy and/or thoracotomy, surgery involving great vessels and serum potassium less than 3.5 mEq/L are employed in this program. The prediction values were higher in the normotensive group(10.2±15.3%) than the hypertensive group(7.9±6.9%), and two cases of perioperative myocardiac infarction occurred in the normotensive group. Histories of myocardiac infarction in the normotensive patients(14.3%) were significantly more frequent than in the hypertensive group(3.3%). The authors suggested that the patients history of hypertension seems not to be directily related to the prediction value of perioperative myocardiac infarction and cardiac mortality.