Purpose: In this study, we aimed to evaluate the laboratory markers used in the diagnosis of COVID-19 and to present the parameters that can be used to predict mortality. Material and method: The cases followed in the intensive care unit due to COVID-19 in our clinic between March 2020 and December 2020 were evaluated retrospectively. A total of 374 patients who met the study criteria were included in the study. The patients were divided into two groups as the patients who were discharged from the intensive care unit with no mortality and patients with a mortal course. Patients with no mortality constituted Group-1, and patients with a mortal course constituted Group-2. Demographic, clinical, and laboratory characteristics of the patients were compared. Results: The number of patients in group-1 consisting of patients with no mortality was 148 (39.5%), and the number of patients in group-2 consisting of patients with mortality was 226 (60.4%). In the group of patients without mortality, 84 (56.8%) of the patients were male, while in the mortality group, 127 (56.2%) were male. In the mortality group, procalcitonin, CRP, BUN, D-dimer, troponin, LDH, lactate, and INR values were higher, albumin value was lower, and this difference was statistically significant (p<0.001). In the logistic regression analysis, PLT and D-dimer were found as the independent variables of mortality. Conclusion: We think that the high procalcitonin and D-dimer values obtained with routinely examined rapid and easily accessible blood tests of Covid-19 patients may contribute to mortality prediction.