To confirm the usefulness of the cardiac risk index published by Goldman and associates in 1977, the author did a separate, prospective study of 1140 patients over the age of 40 years who underwent noncardiac surgical procedures. Four risk categories were defined (classes I to IV, low to high risk according to Goldman's point score). Percentages of postoperative cardiac events (life-threatening cardiac complications or cardiac death) were tabulated. The incidence of cardiac events for each risk category, classes I to IV, was 0.7%, 3%, 15% and 30%, respectively. Comparisons with Goldman's original study demonstrate that the cardiac risk index is a reliable, objective and valid method of assessing cardiac risk in patients who undergo elective surgery.