Aim: This study aimed to explore the correlation between the FIB-5 and FIB-4 indices, which assess liver fibrosis, and the grouped duration of heart failure (HF) in a cohort of subjects from the National Health and Nutrition Examination Survey (NHANES) 2015-2020. Methods: The study included 468 participants categorized into three groups based on HF duration: Group 1 (≤1 year, n=91), Group 2 (1-5 years, n=87), and Group 3 (>5 years, n=290). Data were analyzed using Pearson and Spearman correlation analyses to assess relationships between FIB-5, FIB-4, and HF duration. Clinical variables such as age, BMI, ALT, AST, albumin, and platelet count were also considered.Results: The analysis revealed significant correlation between FIB-5 with age (Pearson correlation (r) = -0.29, p<0.0001) but not for HF duration across groups (Spearman correlation (ρ) = -0.010, p=0.8217). The FIB-4 index did not show significant associations with the HF duration group (p=0.6326). The regression analysis also showed no significant predictive relationship between FIB-5 or FIB-4 and the duration of heart failure, further supporting the lack of association between fibrosis indices and HF duration in this cohort.Conclusion: The study found no significant correlation between the FIB-5 and FIB-4 indices and the duration of heart failure in this cohort. These findings suggest that while these fibrosis scores are useful in liver assessment, they may not directly reflect the duration of heart failure in this population. Further studies are needed to explore other potential biomarkers for HF duration.