Background <p>Cardiovascular-kidney-metabolic (CKM) syndrome, defined by the coexistence of cardiovascular disease (CVD), chronic kidney disease, and metabolic disorders, significantly increases mortality risk. This study examines the relationship between dietary patterns and all-cause and CVD mortality in individuals with CKM syndrome.</p> Methods <p>A cohort study was conducted using data obtained from the National Health and Nutrition Examination Survey, which included 16,589 subjects aged 30 years and above during the period from 2005 to 2018. Four dietary quality scores were used: the Alternate Mediterranean Diet Score (AMED), the Alternate Healthy Eating Index (AHEI), the Dietary Approaches to Stop Hypertension (DASH), and the Healthy Eating Index 2020 (HEI-2020). The mean follow-up was 8.2 years, and Cox proportional hazards regression models were used for multivariable adjustment.</p> Results <p>During the follow-up, 2,811 all-cause and 882 CVD-related deaths were recorded. After multivariable adjustment, higher dietary quality scores were inversely associated with mortality risk. For participants in the highest quintile (Q5) of dietary scores, the hazard ratios (HR, 95% CI) for all-cause mortality were: AMED 0.63 (0.55, 0.71), AHEI 0.62 (0.54, 0.71), DASH 0.63 (0.55, 0.72), and HEI-2020 0.70 (0.62, 0.80). In the analysis of CVD mortality risk, the HRs for Q5 versus Q1 were AMED 0.66 (0.53, 0.82), AHEI 0.62 (0.49, 0.79), DASH 0.73 (0.58, 0.93), and HEI-2020 0.79 (0.64, 0.99). Subgroup analyses demonstrated consistent protective effects of dietary patterns across different socioeconomic characteristics.</p> Conclusions <p>High-quality dietary patterns are associated with a lower risk of all-cause and CVD mortality among individuals with CKM syndrome. These findings underscore the potential importance of dietary patterns in mortality outcomes and provide evidence for future intervention research in CKM syndrome management.</p>