Remdesivir has appeared to be the most effective medication against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and is broadly administered to the coronavirus disease 2019 (COVID-19) patients around the world. Remdesivir is an RNA polymerase inhibitor with a broad spectrum of antiviral activities against RNA viruses in in-vitro and in-vivo models of SARS-CoV, the Middle East respiratory syndrome (MERS), and SARS-CoV-2. Remdesivir is the first Food and Drug Administration (FDA) approved anti-SARS-CoV-2 treatment for adult and pediatric patients and has been used intravenously for patients requiring hospitalization for COVID-19. However, questions have been raised about the value of remdesivir in treating COVID-19, and governing bodies worldwide have been hesitant to approve this medication. Nevertheless, in the context of the public health emergency and the urgent need for effective treatments for patients with COVID-19, remdesivir has been approved by several authorities worldwide. Here, we discuss characteristics and applications of remdesivir, and various challenging studies with different outcomes about its efficacy are also reviewed.