BackgroundLife's Essential 8 (LE8), an indicator of cardiovascular health (CVH), can predict overall and cardiovascular mortality in the general population. Considering that cancer survivors have a higher risk of cardiovascular disease (CVD), our study aimed to investigate the association between LE8 and the prognosis of cancer survivors. MethodsA total of 2191 cancer survivors were included from the National Health and Nutrition Examination Survey (2005–2018). LE8 scores, derived from eight individual metrics, were categorized into three groups: low (0–49), moderate (50–79), and high (80–100). Cox regression analysis, nonlinear analysis, sensitivity analysis, and subgroup analysis were conducted to explore the association between LE8 scores and mortality risks, adjusting for potential confounders. ResultsDuring a median follow-up of six years, 479 deaths were recorded, including 118 CVD events and 156 cancer events. LE8 scores showed an inverse linear relationship with all-cause and cardiovascular mortality. A 10-point increase in LE8 scores was associated with a 25 % reduction in all-cause mortality (hazard ratio [HR], 0.75; 95 % CI, 0.66–0.85) and a 29 % reduction in cardiovascular mortality (HR, 0.71; 95 % CI, 0.57–0.89). Additionally, moderate CVH was linked to a lower risk of all-cause mortality (HR, 0.55; 95 % CI, 0.37–0.81), while high CVH was associated with an even lower risk (HR, 0.35; 95 % CI, 0.19–0.68). Similarly, moderate CVH demonstrated a decreased risk of cardiovascular mortality (HR, 0.31; 95 % CI, 0.15–0.63), with high CVH showing an even lower risk (HR, 0.23; 95 % CI, 0.09–0.58). However, LE8 scores was not associated with cancer-specific mortality. ConclusionsA higher LE8 score was independently associated with a decreased risk of both all-cause and cardiovascular mortality in cancer survivors, underscoring the significance of optimizing CVH during the survivorship phase of cancer care.