SUMMARY OBJECTIVE: Many laboratory parameters allow to follow up the course of the disease and reveal its clinical severity, particularly in patients with coronavirus disease 2019 (COVID-19) pneumonia. In this study, we aimed to investigate the role of the blood urea nitrogen-to-albumin ratio in predicting the mortality in COVID-19 patients with moderate-to-severe disease who are hospitalized in the intensive care unit. METHODS: A total of 358 patients who were hospitalized in intensive care unit at our hospital between November 1, 2020 and May 15, 2021 were included in this study. During their course of intensive care, surviving patients were included in Group 1 and nonsurviving patients in Group 2. RESULTS: There were no statistically significant differences between the two groups in terms of gender, smoking, and chronic obstructive pulmonary disease rates. In multivariate logistic regression analysis, advanced age (OR 1.038, 95%CI 1.014–1.064, p=0.002), neutrophil-to-lymphocyte ratio (OR 1.226, 95%CI 1.020–1.475, p=0.030), blood urea nitrogen-to-albumin ratio (OR 2.693, 95%CI 2.019–3.593, p<0.001), and chest computed tomography severity score (OR 1.163, 95%CI 1.105–1.225, p<0.001) values were determined as independent predictors for in-hospital mortality. CONCLUSION: In this study, we showed that the blood urea nitrogen-to-albumin ratio, which was previously shown as a predictor of mortality in patients with various pneumonia, was an independent predictor of mortality in patients with COVID-19 pneumonia.