BackgroundThe allostatic load (AL) refers to the cumulative weakening of multiple physiological systems caused by repeated adaptation of the body to stressors There are still no studies have focused on the association between AL and the prognosis of patients with heart failure with preserved ejection fraction (HFpEF). The present study aimed to investigate the association between AL and adverse outcomes, including mortality and HF admission, among elderly male patients with HFpEF.MethodsWe conducted a prospective cohort study of 1111 elderly male patients with HFpEF, diagnosed between 2015 and 2019 and followed up through 2021. We constructed an AL measure using a combination of 12 biomarkers. The diagnosis of HFpEF was made according to the 2021 European Society of Cardiology guidelines. A Cox proportional hazards model was used to determine the associations between AL and adverse outcomes.ResultsIn multivariate analysis, AL was significantly associated with increased risk of all-cause mortality (medium AL: adjusted hazard ratio [HR] = 2.53; 95% confidence interval [CI] 1.37–4.68; high AL: HR = 4.21; 95% CI 2.27–7.83; per-score increase: HR = 1.31; 95% CI 1.18–1.46), cardiovascular mortality (medium AL: HR = 2.67; 95% CI 1.07–6.68; high AL: HR = 3.13; 95% CI 1.23–7.97; per-score increase: HR = 1.20; 95% CI 1.03–1.40), non-cardiovascular mortality (medium AL: HR = 2.45; 95% CI 1.06–5.63; high AL: HR = 5.81; 95% CI 2.55–10.28; per-score increase: HR = 1.46; 95% CI 1.26–1.69), and HF admission (medium AL: HR = 2.68; 95% CI 1.43–5.01; high AL: HR = 3.24; 95% CI 1.69–6.23; per-score increase: HR = 1.24; 95% CI 1.11–1.39). Consistent results were found in multiple subgroup analyses.ConclusionsA higher AL was associated with poor prognosis in elderly men with HFpEF. AL relies on information that is easily obtained in physical examinations and laboratory parameters and can be assessed in various care and clinical settings to help risk stratification of HFpEF patients.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12877-023-04091-x.