921 patients (>39 years) with either insulin- or non-insulin-dependent diabetes, scheduled to undergo major orthopaedic surgery were randomized to receive perioperative beta blockade (metoprolol) or a placebo. The primary purpose of this study was to determine whether the perioperative administration of metoprolol significantly improved the incidence of the following composite outcome: all-cause mortality, acute myocardial infarction, unstable angina, or congestive heart failure during hospital admission. Results indicated that the study drug did not significantly impact rates of mortality or cardiac complications in diabetic patients undergoing major non-cardiac surgery, when compared to a placebo. Older age, as well as the presence of coronary artery disease or malignant disease were significant predictors for the primary composite outcome following surgery.