Background Dietary vitamin K (K-1 and K-2) may reduce atherosclerotic cardiovascular disease (ASCVD) risk via several mechanisms. However, studies linking vitamin K intake with incident ASCVD are limited. We aimed to determine the relationship between dietary vitamin K intake and ASCVD hospitalizations. Methods and Results In this prospective cohort study, participants from the Danish Diet, Cancer, and Health Study, with no prior ASCVD, completed a food-frequency questionnaire at baseline and were followed up for hospital admissions of ASCVD; ischemic heart disease, ischemic stroke, or peripheral artery disease. Intakes of vitamin K-1 and vitamin K-2 were estimated from the food-frequency questionnaire, and their relationship with ASCVD hospitalizations was determined using Cox proportional hazards models. Among 53 372 Danish citizens with a median (interquartile range) age of 56 (52-60) years, 8726 individuals were hospitalized for any ASCVD during 21 (17-22) years of follow-up. Compared with participants with the lowest vitamin K-1 intakes, participants with the highest intakes had a 21% lower risk of an ASCVD-related hospitalization (hazard ratio, 0.79; 95% CI: 0.74-0.84), after multivariable adjustments for relevant demographic covariates. Likewise for vitamin K-2, the risk of an ASCVD-related hospitalization for participants with the highest intakes was 14% lower than participants with the lowest vitamin K-2 intake (hazard ratio, 0.86; 95% CI, 0.81-0.91). Conclusions Risk of ASCVD was inversely associated with diets high in vitamin K-1 or K-2. The similar inverse associations with both vitamin K-1 and K-2, despite very different dietary sources, highlight the potential importance of vitamin K for ASCVD prevention.