(1) Background: Our aim was to analyze the incidence, procedures, and in-hospital outcomes of myocardial infarction (MI) in Spain (2016–2018) according to sex. (2) Methods: We estimated the incidence of an ST elevation myocardial infarction (STEMI) and non-ST elevation myocardial infarction (NSTEMI) according to sex using the Spanish National Hospital Discharge Database. A matched-pair analysis was used. (3) Results: MI was coded in 156,826 patients aged ≥18 years (111,842 men and 44,984 women). Men showed higher incidence rates (205.0 vs. 77.8 per 100,000; p < 0.001; IRR = 2.81(95%CI:2.78–2.84)). After matching, the use of coronary artery by-pass grafting (CABG) (1.0% vs. 0.7%; p < 0.001) and percutaneous coronary intervention (PCI) (57.8% vs. 52.3%; p < 0.001) was higher among men with an STEMI, whereas the in-hospital mortality (IHM) remained higher among women (11.2% vs. 10.1%; p < 0.001). Likewise, CABG (1.9% vs. 3.3%; p < 0.001) and PCI (33.8% vs. 41.9%; p < 0.001) were less often used among women with an NSTEMI, but no sex-related differences were found in IHM. After adjusting for confounders, IHM was more than twofold higher for both men and women with an STEMI than those with an NSTEMI. Women with an STEMI had a 21% higher mortality risk than men (OR = 1.21(95%CI:1.13–1.29). (4) Conclusion: Men had higher incidence rates of MI than women. Women underwent invasive procedures less often and had a higher IHM when admitted for an STEMI.