Background and Objectives: Hospital readmissions serve as a significant negative prognostic indicator and have a considerable impact on healthcare utilization among individuals diagnosed with heart failure with preserved ejection fraction (HFpEF). For our study, we aimed to elucidate predictors and trends of HFpEF readmissions within a 30-day period. Methods: The Healthcare Cost and Utilization Project National Readmission Database (NRD) was queried between 2016–2020 to study the 30-day all-cause hospital readmission rate, predictors, duration of hospital stay, and the overall cost of hospitalization. Multivariate/univariate logistic and linear regression analysis were used to analyze the outcomes and adjust for possible confounders. Results: A total of 3,831,156 index hospitalizations for acute decompensated HFpEF were identified between the years 2016–2020, of which 673,844 (18.4%) patients were readmitted within 30 days. The 30-day all-cause readmissions increased significantly from 17.4% to 19.9% (p<0.001) in the 5-year trend analysis. The most common cardiovascular cause for readmission was hypertensive heart disease with chronic kidney disease stage 1–4 (13.2%). Independent predictors associated with increased rate of readmissions were patients that left against medical advice (adjusted odds ratio [aOR], 2.06; 95% confidence interval [CI], 1.99–2.14; p<0.001), cirrhosis (aOR, 1.33; 95% CI, 1.30–1.36; p<0.001), and chronic obstructive pulmonary disease (aOR, 1.27;95% CI, 1.25–1.29; p<0.001). Conclusions Nearly 1 in 5 patients with acute decompensated HFpEF were readmitted within 30 days (2016–2020), with readmissions rising over time. Identifying at-risk patients is crucial to reducing readmissions and costs.