The investigators assessed preoperative health-related quality of life as a predictor of 6-month mortality after cardiac surgery in older (65 years of age and older) vs. younger patients. Multivariable regression, stratified by age groups, was used to compare the association between preoperative Physical Component Summary and Mental Component Summary scores from the Short Form-36 health status survey and mortality. In multivariable analyses of older patients, lower preoperative Physical Component Summary (odds ratio, 1.54; 95% confidence interval, 1.19-2.00; p=0.01) and Mental Component Summary (odds ratio, 1.26; 95% confidence interval, 1.06-1.49; p=0.03) scores were independently associated with mortality. In contrast, neither Physical Component Summary (p=0.82) nor Mental Component Summary (p=0.79) scores were associated with mortality in the younger subgroup. This study demonstrated that preoperative health status is an independent predictor of mortality following cardiac surgery in older but not younger patients. Preoperative patient self-report of health status may be particularly useful in refining risk stratification and informing decision-making before and following cardiac surgery in older patients.