Introduction: For patients with ST-elevation myocardial infarction (STEMI), time is myocardium. The sooner STEMI patients receive a definitive intervention, the better their outcomes. The first point of contact with the healthcare system for STEMI patients is either via Emergency Medical Services (EMS), or self-transportation to an Emergency Department (ED). Despite a reduced time to definitive intervention, STEMI patients who use EMS have increased mortality compared to those who self-transport. In an effort to optimize STEMI care pathways, we characterized variations in modes of presentation of STEMI patients in our region. Methods: This study used a retrospective cohort design from a regional STEMI registry. Patients presenting to Hamilton Health Sciences between January 1, 2016, and December 31, 2018 meeting STEMI criteria were included in our analyses. Self-transport patients were analyzed from two academic EDs in Hamilton, Ontario. One hospital was PCI capable and the other, non-PCI capable. Patients transferred from other health regions were excluded from our analyses. Dichotomous variables were compared using χ2 tests. Group means were compared using the Student t-test. Results: Eight hundred and seventy-one patients were included in the analysis, including 675 EMS users, and 196 self-transporting to EDs. Patients self-transporting to EDs were younger (61.5 v. 64.6 y, p < 0.002) and more often male (82.6 v. 69.2%, p < 0.0002) compared to EMS users. There was a non-significant trend towards an increased rate of all STEMI patients self-transporting in the summer months compared to the winter (63 of 215 in summer v. 41 of 185 in winter, 29.3 v. 22.2%, p = 0.10). Comparative analysis between both hospitals yielded an increased rate of self-transportation to the PCI-capable hospital in the summer months compared to winter (46 v. 28, 23.2 v. 16.3%, p = 0.09), but not the other hospital (18 v. 13, 10.6 v. 8.3%, p = 0.57). The majority of self-transporting patients came from postal codes bordering each hospital, and the different rates of self-transportation between hospitals were not associated with recent specialist follow up at those sites. Conclusion: Seasonal trends in modes of presentation in STEMI patients may present an opportunity to optimize STEMI care pathways through resource utilization and patient education. A larger dataset and possible multicenter analysis should be done to determine if significance is obtained with larger sample size.