The study is aimed to investigate the association between different corticosteroid treatment regimens and clinical status, complications, mechanical ventilation requirement, and intensive care unit (ICU) mortality in individuals diagnosed with Coronavirus Disease of 2019 (COVID-19). This is a descriptive retrospective study. Patients admitted to the ICU for COVID-19 and treated with low- or medium-dose corticosteroid therapy (methylprednisolone at a dose of 0.5-1 mg/kg for 7-10 days) were compared with patients treated with high-dose pulse corticosteroid therapy (methylprednisolone at varying doses of 250 mg, 500 mg or 1000 mg for 3-7 days) in addition to standard therapy because of increased pulmonary infiltrate and elevated inflammatory markers during clinical monitoring. All demographic and clinical data, including age, sex, clinical course, laboratory findings, discharge status, 28-day mortality, intubation status, acute physiological assessment and chronic health evaluation II score, Charlson Comorbidity Index, and sequential organ failure assessment score, were recorded. Corticosteroid treatment was administered to 689 (88.3%) of 780 COVID-19 ICU patients between April 2020 and October 2021. The overall mortality rate was 45.1% (n= 352). When the mortality rates of patients were compared according to the corticosteroid dose, the mortality rate in the low-to-medium-dose group (40%) was significantly lower than that in the high-dose group (76%). In addition, significant deterioration in laboratory and clinical parameters was observed in the high-dose corticosteroid group. High mortality, adverse effects, and complications were significantly increased when high-dose corticosteroids were administered. Corticosteroid therapy should be used cautiously according to the patient's clinical condition, disease stage, comorbidities, and systemic or organ reserves.