The triglyceride glucose-body mass index (TyG-BMI) has emerged as a predictor of complications in patients with heart failure (HF). While elevated TyG-BMI levels have been linked to adverse outcomes in HF patients, their predictive value for acute kidney injury (AKI) risk remains unclear. This study aimed to examine the association between TyG-BMI and the incidence of AKI in patients with HF.Data were obtained from the Medical Information Mart for Intensive Care-IV version 3.1 (MIMIC-IV v3.1) and the eICU Collaborative Research Database version 2.0 (eICU-CRD v2.0). The primary outcome was the occurrence of AKI, with secondary outcomes including the need for renal replacement therapy (RRT) and in-hospital mortality. Kaplan-Meier survival analysis, restricted cubic spline modeling, and Cox proportional hazards regression models were used to assess the associations between TyG-BMI and clinical outcomes.The study included 1,250 patients from MIMIC-IV and 2,300 patients from eICU-CRD. Patients with higher TyG-BMI levels had a significantly higher cumulative incidence of AKI and increased rates of RRT use and in-hospital mortality. After adjusting for potential confounders, higher TyG-BMI remained independently associated with an increased risk of AKI among HF patients in multivariable models.This multicenter analysis demonstrates that higher TyG-BMI levels are associated with an increased risk of AKI, greater need for RRT, and higher in-hospital mortality in patients with HF. TyG-BMI may serve as a useful marker for early risk stratification and prognostic assessment in this population. Further prospective studies are needed to validate these findings.