Background: The aim of the study was to determine the effectiveness of tocilizumab treatment in patients with COVID-19. Methods: 60 patients infected with SARS-CoV-2 were enrolled in the study. The patients were divided into two groups according to whether they treated with tocilizumab or did not. Demographic and clinical features of the patients, laboratory findings, treatments, and clinical outcome were evaluated. Results: The mean age of 30 patients in group 1 was 63.6±16.3 years and male/female ratio was 3.2, whereas the mean age of 30 patients in group 2 was 59.4±11 years and male/female ratio was 2.7 (P=0.244 and P=0.766, respectively). pO2/FiO2 and lymphocyte count at baseline, 2nd day and 7th day were significantly lower in group 1 treated with standard treatment without tocilizumab than group 2 additionally treated with tocilizumab (P<0.05). D-dimer level at 7th day, ferritin and CRP levels at 2nd and 7th day were significantly higher in group 1 than group 2 (P=0.015, P<0.001, P<0.001, P<0.001, P<0.001, respectively). The patients in group 1 had higher intensive care unit need and mortality rate than the patients in tocilizumab group (P=0.015). 28-day survival was lower in group 1 than tocilizumab group (P=0.024). Conclusions: We observed clinical improvement and lower mortality rate in hospitalized patients with severe COVID-19 with tocilizumab treatment.