Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 13 6 2021 12 15 728 736 Mahshid Talebi-Taher Department of Infectious Diseases and Tropical Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Mohammad Hosein Najafi Department of Cardiology, School of Medicine, Azad University, Tehran, Iran Shima Behzad Department of Cardiology, School of Medicine, Azad University, Tehran, Iran 2021 11 01 2021 12 05 Coronavirus disease 2019 (COVID-19), the first pandemic caused by a human infecting coronavirus, has drawn global attention from the first time it appeared in Wuhan city of China in late December 2019. Detection of the responsible viral pathogen, named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by WHO, and its possible pathogenesis lead to the forming of many hypotheses about the factors that may affect the patients’ outcome. One of the SARS-CoV-2 infection concerns was the potential role of angiotensin-converting enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs) in COVID-19 patients’ morbidity and mortality. Studies demonstrated that because SARS-CoV-2 uses human ACE2 cell receptors as an entry receptor to invade the cells, there might be an association between antihypertensive drugs such as RAAS inhibitors (specifically ACEIs and ARBs) and the COVID-19 disease. Data are scarce and conflicting regarding ACEI or ARB consumption and how it influences disease outcomes, and a single conclusion has not been reached yet. According to the literature review in our article, the most evidentially supported theory about the use of RAAS inhibitors in COVID-19 is that these medications, including ACEI/ARB, are not associated with the increased risk of infection, disease severity, and patient prognosis. However, further studies are needed to support the hypothesis. https://ijm.tums.ac.ir/index.php/ijm/article/view/3398 https://ijm.tums.ac.ir/index.php/ijm/article/download/3398/1399