Supported by a grant (MC_PC_19056) to the University of Oxford from the Medical Research Council of United Kingdom Research and Innovation and the National Institute for Health Research (NIHR); and by core funding provided by NIHR Oxford Biomedical Research Centre, Wellcome, the Bill and Melinda Gates Foundation, the Department for International Development, Health Data Research UK, the Medical Research Council Population Health Research Unit, the NIHR Health Protection Unit in Emerging and Zoonotic Infections, and NIHR Clinical Trials Unit Support Funding. Dr. Lim is supported by core funding provided by NIHR Nottingham Biomedical Research Centre, Dr. Felton by the NIHR Manchester Biomedical Research Centre, and Dr. Jaki by a grant (MC_UU_0002/14) from the UK Medical Research Council and by an NIHR Senior Research Fellowship (NIHR-SRF-2015-08-001). BACKGROUND: Coronavirus disease 2019 (Covid-19) is associated with diffuse lung damage. Glucocorticoids may modulate inflammation-mediated lung injury and thereby reduce progression to respiratory failure and death. METHODS: In this controlled, open-label trial comparing a range of possible treatments in patients who were hospitalized with Covid-19, we randomly assigned patients to receive oral or intravenous dexamethasone (at a dose of 6 mg once daily) for up to 10 days or to receive usual care alone. The primary outcome was 28-day mortality. Here, we report the final results of this assessment. RESULTS: A total of 2104 patients were assigned to receive dexamethasone and 4321 to receive usual care. Overall, 482 patients (22.9%) in the dexamethasone group and 1110 patients (25.7%) in the usual care group died within 28 days after randomization (age-adjusted rate ratio, 0.83; 95% confidence interval [CI], 0.75 to 0.93; P