Tehran University of Medical Sciences Frontiers in Emergency Medicine 2717-3593 6 2 2022 01 11 e23 e23 Peyman Saberian Prehospital and Hospital Emergency Research Center, Tehran University of Medical Sciences, Tehran, Iran Seyed-Hossein Seyed-Hosseini-Davarani Department of Emergency Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Mahtab Ramezani Department of Neurology, Skull Base Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Sahar Mirbaha Department of Emergency Medicine, Shohadaye Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mahdi Zangi Prehospital and Hospital Emergency Research Center, Tehran University of Medical Sciences, Tehran, Iran Sepideh Aarabi Prehospital and Hospital Emergency Research Center, Tehran University of Medical Sciences, Tehran, Iran 2021 09 17 2021 09 28 Objective: We conducted this study to evaluate the prevalence of concomitant COVID-19 in acute ischemic stroke (AIS) patients admitted to stroke centers of Tehran, Iran. Methods: We conducted a retrospective cross-sectional study in a 45-day period. AIS patients transferred by emergency medical service (EMS) to all medical centers of the city were included. Information was recorded and compared in two groups: patients who tested positive for COVID-19 and those who were negative. Result: Emergency medical technicians (EMTs) screened 348 patients as AIS cases, of whom, AIS was ultimately confirmed in 311 (89.4%) patients; and 58 (18.6%) of the 311 AIS patients were diagnosed with concomitant COVID-19 infection. The National Institutes of Health Stroke Scale (NIHSS) scores of COVID-19 positive AIS patients were significantly higher than non-COVID-19 AIS patients (16.3±3.7 vs. 11.8±4.3; p<0.001). There was also a significant difference in length of hospital stay between the two groups (11.1±1.8 vs. 8.8±4.3 days; p<0.001). However, data showed no significant difference regarding prevalence of in-hospital mortality between the two groups (1.6% vs. 3.5%; p=0.320). Conclusion: Our study results showed that AIS patients with concomitant COVID-19 infection had higher NIHSS scores and longer length of hospital stay compared to patients without concomitant COVID-19 infection. https://fem.tums.ac.ir/index.php/fem/article/view/863 https://fem.tums.ac.ir/index.php/fem/article/download/863/385