Studies on the long-term differences in quality-of-life (QoL) metrics after treatment for stable ischemic heart disease (SIHD) in older adults with diabetes mellitus are lacking. Older patients (age ≥65 years) in the BARI 2D trial were stratified into those who received intensive medical therapy (IMT) only versus revascularization (PCI vs CABG) with OMT. Self-health Score, Duke Activity Status Index, Energy Rating, and Health Distress Rating at 5 years were compared using multivariable linear regression. A total of 929 older adults were included, of which 469 (50.5%) underwent medical therapy alone, 302 (32.5%) underwent PCI, and 158 (17.0%) patients had CABG. Patients who underwent CABG were more likely to have proximal left anterior descending coronary artery disease, chronic total occlusion, and higher myocardial jeopardy index. At 5 years of follow-up, no differences in self-health Score, Duke activity status index, energy rating, and health distress rating were observed between PCI and IMT. There are also no differences in the four QoL measures between CABG and IMT alone. However, the Duke Activity Status Index was marginally higher with CABG but not statistically significant (mean difference 3.88, 95% CI: -0.10, -7.86, p=0.057). At 5 years of follow-up, no differences in QoL measures were observed between PCI and CABG with OMT versus OMT alone in older adult patients with diabetes mellitus and SIHD. Future blinded randomized trials are necessary to investigate the impact of SIHD treatment on the older adult population, taking into account the risks associated with multimorbidity, polypharmacy, frailty, and cognitive impairment.