Although payers increasingly report information on hospital volume and mortality from surgery, the value of these data is uncertain. Using national Medicare data for six surgical operations (covering the years 2003-2006), we created a composite measure based on these two quality indicators. We found that this simple measure was a strong predictor of future performance for all six operations. In this regard, it was more effective than the individual measures. Such measures would be useful for helping patients and payers identify low-mortality hospitals for major surgery.