Aims We hypothesize that poor quality of life (QOL) is highly prevalent in frail older adults and is associated with worse prognosis.Methods and results Predismissal standardized tests for frailty and QOL were prospectively administered to patients included in two cohorts. In Cohort 1, 629 patients >= 65 years who underwent percutaneous coronary intervention (PCI) from 2005 to 2008, frailty (Fried criteria), and QOL [SF-36 and Seattle Angina Questionnaires (SAQ)] were ascertained. Cohort 2 included 921 patients >= 55 years who underwent cardiac catheterization (535 had PCI) from 2014 to 2018 and frailty was determined by Rockwood criteria and QOL by single-item, self-reported health questionnaire. In Cohort 1, 19% were frail and 20% patients in Cohort 2 were frail with a frailty index >0.30. The median SAQ for physical limitation (58.9 vs. 82.2, P<0.001), physical (29.5 vs. 43.9, P<0.001), and mental (49.2 vs. 57.4, P<0.001) component scores of SF-36 in Cohort 1 were lower and self-rating of fair/poor health (56% vs 18%, P<0.001) in Cohort 2 was significantly higher in frail patients. As compared to patients without frailty, frail patients were five times more likely (59% vs. 11%, P<0.001) in Cohort 1 and seven times more likely (56% vs. 8%) in Cohort 2 to be classified with poor QOL. Age- and gender-adjusted 3-year all-cause death and death or myocardial infarction (MI) was significantly higher for patients undergoing PCI with frailty; [hazard ratio (95% confidence interval) death, 4.20 (2.63-6.68, P<0.001) and death or MI hazard ratio (HR) 2.72 (1.91-3.87, P<0.001)] and with poor QOL [HR death 2.47 (1.59-3.84, P<0.001)] and death or MI 1.61 (1.16-2.24, P<0.001). There was no significant interaction between frailty and QOL (P=0.64) and only modest attenuation was observed when considered together indicating their independent prognostic influence.Conclusion In elderly patients undergoing cardiac catheterization or PCI, poor QOL is seen more frequently in frail patients. Both frailty and poor QOL had significant and independent association with long-term survival.