BACKGROUND: An unhealthy diet is a major contributor to several noncommunicable diseases, including cardiovascular diseases, the leading cause of death worldwide. Additionally, our food system has significant impacts on the environment. The EAT-Lancet Commission has recommended a healthy diet that preserves global environmental resources. OBJECTIVES: This prospective study aimed to evaluate the associations between adherence to the EAT-Lancet diet and the incidence of cardiovascular events and all-cause mortality in a Swiss cohort. METHODS: We analyzed data from the CoLaus/PsyCoLaus cohort study (N = 3866). Dietary intake was assessed using a semiquantitative food frequency questionnaire. The EAT-Lancet adherence score was calculated based on the recommended intake and reference intervals of 12 food components, ranging from 0 to 39 points. Participants were categorized into low-, medium-, and high-adherence groups according to score tertiles. We used Cox Proportional Hazards regressions to assess the association among diet adherence, incident cardiovascular events, and all-cause mortality. RESULTS: During a mean follow-up of 7.9 y (SD: ±2.0 y), 294 individuals (7.6%) from our initial sample experienced a first cardiovascular event, and 264 (6.8%) died. Compared with the low-adherence group, the adjusted hazard ratios for all-cause mortality were 0.88 (95% CI: 0.66, 1.17) and 0.70 (95% CI: 0.49, 0.98) for the medium-adherence and high-adherence groups, respectively (P-trend = 0.04). We observed no association between adherence groups and cardiovascular events. CONCLUSIONS: In a Swiss cohort, high adherence to the EAT-Lancet diet is associated with a potential 30% lower risk of overall mortality. However, it is not associated with cardiovascular events.