Background and aims: Chronic kidney disease (CKD) is present in >30% of patients with acute myocardial infarction (MI) and has been associated with lower rates of guideline-directed management and worse prognosis. We investigated the use of guideline-directed management and mortality risk in patients with and without CKD. Methods: A nationwide cohort study based on health care registers encompassing all patients ≥18 years hospitalized with first-time MI in Denmark from 2010-2022 was conducted. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m². Probability of guideline-directed management and risk of all-cause mortality in patients with and without CKD were calculated from adjusted multivariable logistic and Cox regression models with probabilities and risks standardized to the distribution of confounders in the population. Results: In total, we identified 21,009 patients who met eligibility criteria. Median age was 72 years, and 61% of patients were males; the median eGFR was 82 ml/min/1.73 m², and 21% of patients had CKD. The 30-day probabilities of coronary angiography and revascularization were 71% (95% CI 69%-72%) and 78% (95% CI 77-79%), p<0.001; and 52% (95% CI 50%-54%) and 58% (95% CI 58%-59%), p<0.001, in patients with and without CKD, respectively. Probabilities increased during the study period (p for trend 0.05, 0.03, 0.02 and 0.03, respectively). In patients with and without CKD, probability of dual antiplatelet therapy was 67% (95% CI 65%-68%) and 70% (95% CI 69%-71%), p=0.001; while probability of lipid-lowering treatment was 76% (95% CI 75%-78%) and 82% (95% CI 81%-83%), p<0.001. Associated one-year mortality was 21% (95% CI 20%-22%) and 16.4% (95% CI 16%-17%) in patients with and without CKD, respectively. with decreasing mortality rates in both groups during the study period (p for trend 0.03 and 0.01). Conclusions: Although survival following MI improved for all patients, CKD continued to be associated with lower use of guideline-directed management and higher mortality.