Background: The role of angiotensin-converting enzyme (ACE) inhibitors in patients with heart failure and preserved ejection fraction remains unclear. Methods: Of the 10,570 patients aged ≥65 years with heart failure and preserved ejection fraction (≥40%) in the Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients With Heart Failure (2003-2004) linked to Medicare (through December 2008), 7304 were not receiving angiotensin receptor blockers and had no contraindications to ACE inhibitors. After excluding 3115 patients with pre-admission ACE inhibitor use, the remaining 4189 were eligible for new discharge prescriptions for ACE inhibitors, and 1706 received them. Propensity scores for the receipt of ACE inhibitors, calculated for each of the 4189 patients, were used to assemble a cohort of 1337 pairs of patients, balanced on 114 baseline characteristics. Results: Matched patients had a mean age of 81 years and mean ejection fraction of 55%, 64% were women, and 9% were African American. Initiation of ACE inhibitor therapy was associated with a lower risk of the primary composite end point of all-cause mortality or heart failure hospitalization during 2.4 years of median follow-up (hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.84-0.99; P =.028), but not with individual end points of all-cause mortality (HR, 0.96; 95% CI, 0.88-1.05; P =.373) or heart failure hospitalization (HR, 0.93; 95% CI, 0.83-1.05; P =.257). Conclusion: In hospitalized older patients with heart failure and preserved ejection fraction not receiving angiotensin receptor blockers, discharge initiation of ACE inhibitor therapy was associated with a modest improvement in the composite end point of total mortality or heart failure hospitalization but had no association with individual end point components. © 2013 Elsevier Inc.