BACKGROUND: Cardiovascular disease (CVD) is a leading cause of global mortality, with increasing prevalence and impact, especially in the elderly and developing countries. Insulin resistance (IR) plays a significant role in CVD progression, and the triglyceride glucose-body mass index (TyG-BMI) index, combining fasting glucose and triglycerides, offers a simple, cost-effective method for assessing IR. However, its prognostic value in CVD populations remains underexplored. This study aims to investigate the relationship between TyG-BMI and mortality in CVD patients. METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) (1999-2018) combined with the linked National Death Index were analyzed. The CVD population was split into two groups (Q1 and Q2) based on the median TyG-BMI. The primary outcomes were all-cause mortality and cause-specific mortality. RESULTS: The study ultimately included 2,576 participants, of which 56% were male. The median age of the participants was 69 years, and the median TyG-BMI was 256.59. After adjusting for potential confounders, a negative relationship was found between TyG-BMI and all-cause mortality in populations with CVD, coronary heart disease (CHD), congestive heart failure (CHF), and heart attack. The hazard ratios (HR) and 95% confidence intervals (CI) were 0.73 (0.64, 0.85), 0.67 (0.53, 0.84), 0.69 (0.54, 0.88), and 0.73 (0.59, 0.91), respectively. At the same time, a notable inverse relationship was noted between the TyG-BMI and non-CVD mortality in the CVD and CHD population, with HR and 95% CI of 0.70 (0.58, 0.84) and 0.61 (0.45, 0.82), respectively. In this study, there was no observed noteworthy relationship between TyG-BMI and CVD mortality. Furthermore, sensitivity analysis yielded similar results. CONCLUSION: Among populations with CVD in the United States, a heightened TyG-BMI was notably correlated with a decreased likelihood of mortality. This index can effectively classify the risk levels of CVD patients and may serve as a valuable prognostic marker.