Aims: This study was performed to evaluate risk factors for mortality in patients with Coronavirus disease 2019 (COVID-19) receiving respiratory support. Methods: This retrospective multicenter cohort study was undertaken in the Daegu and Gyeongsangbuk-do area, South Korea. The clinical and laboratory features of patients with COVID-19 receiving respiratory support were analyzed to ascertain the risk factors for mortality. Results: Of the1005 patients with a confirmed diagnosis of COVID-19, 289 (28.8%) received respiratory support and of these, 70 patients (24.2%) died. In multivariate analysis, high fibrosis-4 index (HR 2.784; 95% CI 1.691-4.585; P<0.001), low lymphocyte count (HR 0.480; 95% CI 0.271-0.852; P=0.012), diabetes (HR 1.917; 95% CI 1.181-3.111; P=0.009), and systemic inflammatory response syndrome (HR 1.714; 95% CI 1.048-2.802; P=0.032) were found to be independent risk factors for mortality in patients with COVID-19 receiving respiratory support. Regardless of respiratory support, fibrosis-4 index was found to be a robust predictive marker for mortality in patients with COVID-19 (P<0.001). A number of risk factors were also significantly related to survival in patients with COVID-19 regardless of respiratory support (P<0.001). Conclusions: Fibrosis-4 index is a useful predictive marker for mortality in COVID-19 patients regardless of its severity.