Efficiency of various inflammation-based indices, including neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), C-reactive protein/lymphocyte ratio (CLR), albumin/globulin ratio (AGR), haemoglobin, albumin, lymphocyte, and platelet (HALP), systemic immune-inflammatory index (SII) and prognostic nutritional index (PNI), was examined in predicting mortality in COVID-19 patients. The study population consisted of 827 COVID-19 patients, including 733 survivors and 94 non-survivors. Compared with the survivor group, the NLR, PLR, CLR, and SII values of the non-survivor group were markedly higher; however, the LMR, PNI, HALP and AGR values were markedly lower. Multivariate analysis identified PNI, NLR, CLR, older age, male gender and dyslipidemia as independent factors for mortality in COVID-19 patients. PNI had the largest area under the curve to predict mortality, followed by CLR, NLR, and other indexes. This data revealed that PNI, NLR, and CLR are independent factors of mortality in COVID-19 patients among inflammation-based indexes. Key Words: COVID-19 mortality, Prognostic nutritional index, C-reactive protein/lymphocyte ratio, Neutrophil/lymphocyte ratio.