Aim: Schizophrenia is associated with high cardiovascular mortality predominantly as a result of acute coronary syndrome (ACS). The aim of this study is to analyze time trends of coronary procedures, guideline-based therapy, and allcause mortality in patients diagnosed with schizophrenia. Methods and Results: This Danish nationwide registerbased study analyzed 734 patients with a baseline diagnosis of schizophrenia and an incident diagnosis of ACS in the period between January 1, 1996, and December 31, 2015. The 734 patients with schizophrenia were matched to 2,202 psychiatric healthy controls (PHC). No change over time was seen in the relative difference between the population with schizophrenia and the PHC in the use of coronary angiography, percutaneous coronary intervention, and coronary bypass grafting, nor in 1-year mortality or guideline-based therapy following ACS. Patients with schizophrenia had higher prevalence rates of diabetes, chronic obstructive pulmonary disease, and stroke, and a lower prevalence of hypertension (p < 0.05). Conclusion: The gap in the use of coronary procedures, guideline-based therapy, and all-cause mortality following ACS in patients with schizophrenia compared to those without has remained constant over the past 2 decades.