SARS-CoV-2 (COVID-19) has infected over 100 million people since it appeared in Wuhan, China just 1 year ago. This study aimed to evaluate the relationship between interleukin-6 (IL-6)gene polymorphisms -174G/C and -597G/A and COVID-19 course. The study included a total of 70 patients aged 18–45 years who were hospitalized in our hospital and diagnosed with COVID-19 in Turkey between March and November 2020. Of these, 40 patients required intensive care admission due to macrophage activation syndrome (MAS) and 30 patients did not develop MAS or acute respiratory distress syndrome. The frequency of IL-6-174G/C -and 597G/A polymorphisms was determined. There were statistically significant differences between the groups in terms of -174G/C allele and genotype frequency and comparison with Hardy-Weinberg distribution (χ²=10.029, df=1, p=0.002 and χ²=9.998, df=1, p=0.002, respectively). The frequency of the GG genotype was significantly higher in the MAS group compared to the non-MAS group (p=0.002). The G allele was also significantly more frequent in the MAS group compared to the non-MAS group (p=0.032). Analysis of the -174G/C polymorphism in patients with MAS showed that the G allele may be a risk factor for increased serum IL-6 levels and progression to MAS.