Background: Heart failure with preserved ejection fraction (HFpEF) represents more than one half of the heart failure (HF) cases worldwide with increased morbidity and mortality. No proven medical treatment till now has shown mortality benefit in HFpEF. This study aims to elucidate the benefit of cardiac rehabilitation (CR) in HFpEF.Methods: 60 patients with HFpEF included in 2 groups with 1:1 randomization. The first group (the rehabilitation group) received usual medical care plus 2-3 rehabilitation sessions per week for 12 weeks using moderate intensity exercise with 40-75% of heart rate reserve on treadmill (up to 60 minutes according to the functional capacity). The second group (the control group) received only usual medical care. Comparison between the 2 groups using the percentage of improvement in echocardiographic diastolic function parameters, Minnesota living with heart failure questionnaire (MLWHFQ) and 6 -minute walk test at baseline and after 12 weeks.Results: we found statistically significant difference between the two groups in favor of the rehabilitation group in the following parameters: a. MLWHFQ (total score mean percentage of reduction) 305.60 ± 158.44 versus (vs.) 69.44 ± 17.71 (p < 0.001). b. E/e` mean percentage of reduction 65.96 ± 34.55 vs. 18.23 ± 13.98 (p < 0.001). c. Left atrial volume index (LAVI) mean percentage of reduction 27.86 ± 13.27 vs. 8.03 ± 4.40 (p < 0.001). d. Pulmonary artery systolic pressure mean percentage of reduction was 33.85 ± 14.68 vs. 22.97 ± 16.54 (p=0.02). e. 6–minute walk test 111.79 ± 40.97 vs. 46.33 ± 11.58 (p < 0.001). f. Body mass index percentage of reduction 10.17 ± 3.64 vs. 2.80 ± 1.60 p < 0.001. g. Percentage of patients with down-grading of the grade of diastolic dysfunction 10 patients (33.3%) vs. 3 patients (10%) (P=0.028). h. No significant difference in left ventricular ejection fraction or other parameters as E/A ratio, left atrial dimension , isovolumetric relaxation time, degree of left ventricular hypertrophy.Conclusion: Cardiac rehabilitation not only added significant functional improvement in the quality of life and functional capacity but also a significant structural improvement by improving the core items of diastolic function. In the Light of this study, we recommend exercise training based cardiac rehabilitation in HFpEF management