Background: Heart failure with preserved ejection fraction (HFpEF) has several pathophysiological aspects including stiffness of multiple organs. It has been recently reported that liver stiffness assessed by transient elastography predicts adverse prognosis in heart failure patients. Liver fibrosis is assessed by nonalcoholic fatty liver disease (NAFLD) fibrosis score (based on age, body mass index, aspartate aminotransferase [AST] to alanine aminotransferase [ALT] ratio, platelet counts and albumin) in patients with NAFLD. We aimed to investigate the impact of NAFLD fibrosis score on prognosis of HFpEF patients. Methods and Results: We analyzed consecutive 510 patients with HFpEF who admitted to our hospital. Out of these 510 HFpEF patients, patients with hepatitis and chronic liver disease were excluded, and 492 patients were finally analyzed. Liver fibrosis was estimated by NAFLD fibrosis score (= - 1.675 + 0.037 х age [years] + 0.094 х body mass index + 1.13 х diabetes mellitus [if presence, given 1] + 0.95 х AST [IU/L]/ ALT [IU/L] - 0.013 х platelet count [10- 9 /L] - 0.66 х albumin [mg/L]). These patients were divided into 4 groups based on the NAFLD fibrosis score: 1 st (NAFLD fibrosis score < -1.13, n = 123), 2 nd (-1.13 ≤ NAFLD fibrosis score < 0.20, n = 123), 3 rd (0.20 ≤ NAFLD fibrosis score <1.56, n = 123) and 4 th (1.56 ≤ NAFLD fibrosis score, n = 123) quartiles. In the follow-up period (mean 1107 days), 93 deaths (33 cardiac deaths and 60 non-cardiac deaths) occurred. In the Kaplan-Meier analysis, all-cause mortality progressively increased from 1 st to 2 nd , 3 rd and 4 th groups (8.1%, 12.2%, 23.6% and 31.7%, P <0.001). In the Cox proportional hazard analysis, after adjusting for potential confounding factors, NAFLD fibrosis score was an independent predictor of all-cause mortality in HFpEF patients (hazard ratio 1.98, 95% confidence interval 1.43-3.19, P < 0.001). Conclusion: NAFLD fibrosis score, a marker of liver fibrosis, can identify high risk patients with HFpEF.