Background: Heart failure is a chronic cardiovascular condition with associated high morbidity, mortality and health-related costs. The disparities of varying sociodemographic factors associated with clinical outcomes in patients with preserved ejection fraction heart failure (HFpEF) is yet to be extensively studied.Aim: To evaluate gender and racial disparities in length of hospital stay (LOS), cost of hospitalization, and in-hospital (IH) mortality in patients with HFpEF.Method: Adults (>18 years) with a primary diagnosis of Acute on Chronic Diastolic dysfunction were identified from the 2016 and 2017 National Inpatient Sample using ICD 10 codes. The relationship between gender or racial groups (Non-Hispanic Whites (NHW)-Ref, Non-Hispanic Blacks (NHB), Hispanics, Asian/Pacific Islanders and Native Americans and study clinical outcomes were assessed using weighted multivariable logistic and linear regression models as appropriate.Results: Among patients with HFpEF (n=595,936), 59.8% were females; 73.4%, 15.6%, 6.6%, 1.9%, and 2.5% were NHW, NHB, Hispanics, Native Americans, and Asians/Pacific Islanders respectively. Females had lower IH mortality [adjusted OR (aOR) 0.9; 95% CI: 0.87 - 0.92) compared to males. Compared to NHW, NHB (aOR 0.81; 95%CI: 0.77 - 0.84) and Hispanics (aOR 0.91; 95%CI: 0.86 - 0.96) had lower odds of IH mortality, while IH mortality in Asian/Pacific Islander and Native American was not significantly different from NHW. Females had lower LOS (mean difference(mD) -0.34 days; 95%CI -0.38 to -0.30) and lower hospital cost (mD -$1967; 95%CI: -2097 to -1838) than males. NHB had similar rates of LOS (mD 0.04days; 95%CI: -0.02 - 0.11) and hospital cost (mD -$176; 95%CI: -412 - 60) compared to NHW. Hispanics had similar rates of LOS but higher hospital cost (mD 0.07 days; 95%CI -0.04 - 0.18; mD $1182; 95%CI: 754 - 1609), Asians/Pacific Islander (mD 0.32 days; 95%CI: 0.14 - 0.49, mD $2846; 95%CI 2173 - 3519) and Native American had a higher LOS and hospital cost compared to NHW (mD 0.49 days; 95%CI: 0.33 - 0.64, mD $2793; 95%CI: 2048 - 3539).Conclusion: Our study highlights racial and gender disparities in important clinical outcomes among patients with HFpEF, buttressing the need to tailor intervention to higher risk groups.