Heart failure with preserved ejection fraction (HFpEF) accounts for half of incident heart failure cases per year. Currently, the diagnostic reference standard is invasive. The objective of this study is to evaluate if cardiac MR elastography (MRE) can measure increased myocardial stiffness in patients with HFpEF. Fifty-eight volunteers and 10 patients were enrolled. The mean left-ventricle myocardial stiffness of HFpEF patients (10.5±1.7 kPa) was significantly higher (p=0.002) than control subjects (8.0±1.2 kPa).This study motivates further investigation into the use of cardiac MRE as a quantitative noninvasive imaging technique to assist in the diagnosis and therapy monitoring of patients with HFpEF.