Heart failure with preserved ejection fraction (EF) is a common syndrome, but trends in treatments and outcomes are lacking. We analyzed data from 275 hospitals in Get With the Guidelines-Heart Failure from January 2005 to October 2010. Patients were stratified by EF as reduced EF (EF <40% [HF-reduced EF]), borderline EF (40%≤EF<50% [HF-borderline EF]), or preserved (EF ≥50% [HF-preserved EF]). Using multivariable models, we examined trends in therapies and outcomes. Among 110 621 patients, 50% (55 083) had HF-reduced EF, 14% (15 184) had HF-borderline EF, and 36% (40 354) had HF-preserved EF. From 2005 to 2010, the proportion of hospitalizations for HF-preserved EF increased from 33% to 39% (P<0.0001). In multivariable analyses, use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers at discharge decreased in all EF groups, and β-blocker use increased. Patients with HF-preserved EF less frequently achieved blood pressure control (adjusted odds ratio, 0.44 versus HF-reduced EF; P<0.001) and were more likely discharged to skilled nursing (adjusted odds ratio, 1.16 versus HF-reduced EF; P<0.001). In-hospital mortality for HF-preserved EF decreased from 3.32% in 2005 to 2.35% in 2010 (adjusted odds ratio, 0.89 per year; P=0.01) but was stable for patients with HF-reduced EF (3.03%-2.83%; adjusted odds ratio, 0.93 per year; P=0.10). Hospitalization for HF-preserved EF is increasing relative to HF-reduced EF. Although in-hospital mortality for patients with HF-preserved EF declined over the study period, an important opportunity remains for identifying evidence-based therapies in patients with HF-preserved EF.