Objective: This was a retrospective investigation conducted to evaluate the impact of the coronavirus disease-2019 (COVID-19) pandemic on the treatment and outcomes of patients with ischemic stroke. Methods: Data were collected over one year for the COVID-19 and pre-COVID-19 (control) groups, from May 1, 2020, to April 30, 2021, when COVID-19 was prevalent in Korea, and from May 1, 2018 to April 30, 2019, before the COVID-19 outbreak, respectively. Adult patients diagnosed with acute cerebral infarction at three emergency medical centers during the study period were included. COVID-19-positive patients (i.e., those with COVID-19 symptoms but those who tested positive) were excluded from this study to ensure only the evaluation of delays in stroke treatment due to the pandemic. Results: During the COVID-19 pandemic, of the total of 82,558 patients who visited the emergency centers, 710 were diagnosed with ischemic stroke. The study observed that the pandemic caused process delays for these patients, resulting in longer wait times for brain CT scans (P=0.010, P<0.001) and emergency room stays (P=0.0055, P<0.001) during the COVID-19 period. However, the length of time for administration of tissue plasminogen activator remained relatively constant. Notably, the 28-day mortality rate was considerably higher for patients with COVID-19-related symptoms during the pandemic (13.6% vs 3.1%; P=0.006). A cumulative risk analysis revealed an increased mortality risk for patients with COVID-19 related symptoms (P=0.005). Conclusion This study showed the need to improve emergency care procedures during pandemics to ensure prompt treatment of ischemic stroke. Preparation and resource allocation for ischemic stroke patients with COVID-19 symptoms are crucial.