© 2021 Ankara Microbiology Society. All rights reserved.Coronaviruses are enveloped, positivepolarity, single-stranded RNA viruses that can cause respiratory and gastrointestinal tract infections, less likely to cause infections with hepatic, neurological and nephrotic involvement. A novel coronavirus termed as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) emerged in the city of Wuhan, China, and caused an outbreak of unusual viral pneumonia at the end of 2019. This study aimed to reveal the relationship between systemic immune-inflammation index (SII), C-reactive protein (CRP) and interleukin-6 (IL-6) and viral dynamics in COVID-19 patients. This retrospective, single-center study was conducted in Ankara City Hospital from April 1 to May 31, 2020. A total of 338 hospitalized patients who had positive results in SARS-CoV-2 reverse transcrytase polymerase chain reaction (RT-PCR) test from nasopharyngeal and oropharyngeal samples during their hospital admission were included in this study. Patients were divided into three groups according to their ward/intensive care unit, intubation and mortality situation and their clinical data were evaluated. Correlation analysis was performed to determine the relationship between viral dynamics and laboratory parameters such as SII, the neutrophil-to-lymphocyte ratio (NLR), the lymphocyte-to-CRP ratio (LCR), the lymphocyte-to-monocyte ratio (LMR), the platelet-to-lymphocyte ratio (PLR), CRP, IL-6 ferritin, albumin levels and lymphocyte count. Advanced age, low Ct value, increase in IL-6, increase in SII, decrease in albumin, increase in ferritin, decrease in lymphocyte count, increase in NLR, decrease in LCR, decrease in LMR, increase in PLR and increase in CRP levels were found statistically significantly different in all three groups (p< 0.001; p= 0.02; p< 0.001; p< 0.001; p< 0.001; p< 0.001; p< 0.001; p< 0.001; p< 0.001; p< 0.001; p< 0.001; p< 0.001, respectively). Statistical analysis revealed a significant negative correlation between serum IL-6, NLR, LCR and CRP values with Ct values (p< 0.01, r= -0.233; p= 0.021, r= -0.126; p=0.004, r= -0.156 and p= 0.011, r= -0.138, respectively) and a significant positive correlation between Ct values and lymphocyte count and albumin levels (p= 0.005; r= 0.151 and p= 0.050; r= 0.106, respectively). Severe progression was observed in patients with advanced age, low Ct value, high IL-6 levels, high SII, hypoalbuminemia, high ferritin levels, lymphopenia, high NLR, low LCR, low LMR, high PLR and high CRP. In these patients hospitalization in intensive care unit, intubation and mortality were found to be higher. High levels of IL-6, NLR, LCR and CRP, lymphopenia and hypoalbuminemia were associated with low PCR Ct values.