Objective The aim of present study was to elucidate the gender differences in social determinants among patients with acute heart failure (AHF). Methods A total of 1,048 AHF patients were enrolled, and the 508 AHF patients who were ! 75 years old and the 540 patients who were <75 years old were evaluated as the elderly and non-elderly cohorts, respectively. Participants who met one of the three marital status-, offspring-, and living status-related criteria were considered socially vulnerable, and subjects were thus classified into socially vulnerable and non-socially vulnerable groups by gender in both the non-elderly and elderly cohorts. Social vulnerability was significantly more common in the elderly cohort (n=246, 48.4%) than in the non-elderly cohort (n=197, 36.5%) and significantly more common in the elderly women (n=157, 69.4%) than in the elderly men (n=89, 31.5%). Kaplan-Meier curves showed that the survival rate of the socially vulnerable group was significantly poorer than that of the non-socially vulnerable group in the elderly male cohort (p=0.010). Social vulnerability was an independent predictor of the 1,000-day mortality in the elderly male cohort (hazard ratio: 1.942, 95% confidence interval: 1.102-3.422) but not in the elderly female cohort according to a multivariate analysis. Conclusion Social vulnerability was shown to be more common in elderly female AHF patients than in elderly men, although it was associated with a poor prognosis in elderly men. Reinforcing the social structure of elderly male AHF patients might help improve their prognosis.