Remdesivir is a direct-acting antiviral agent that inhibits viral RNA synthesis developed by Gilead Sciences, Inc. in the United States. It has been shown to have antiviral activity against single-stranded RNA viruses, including coronaviruses, in cell culture systems and animal models, and has been developed as a therapeutic agent for Ebola virus infection since 2015. however, to date, it has not been approved in any country. A novel coronavirus infection (COVID-19) was identified in Wuhan, Hubei Province, China in Dec, 2019, and is a respiratory disease characterized by fever, cough, and dyspnea. In severe cases, it may cause serious pneumonia, multi-organ failure and death. Gilead Sciences, Inc. U.S. embarked on the development of COVID-19 as a therapeutic drug, using remdesivir, which has shown in vitro and in vivo antiviral activities against MERS-CoV and SARS-CoV, which are single-stranded RNA coronaviruses that cause Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS). The in vitro antiviral activity of remdesivir against SARS-CoV-2, which causes COVID-19, was confirmed and clinical studies were initiated in February 2020. Based on the results of clinical studies conducted by the National Institute of Allergy and Infectious Diseases (NIAID) and Gilead Sciences, Inc. and experience of administration from a compassionate use, an exceptional approval system based on the "Pharmaceuticals and Medical Devices Act" was also approved in Japan as of May 7, 2020 for the indication of "infections caused by SARS-CoV-2." In this article, the background of the development and clinical results of remdesivir are described.