The objective of this case series was to compare the clinical characteristics, radiologic features, and laboratory findings between COVID-19 severe patients admitted to the intensive care unit (ICU) to those with non-severe patients who were not admitted to the ICU. From September 1, 2020, to October 30, 2020, a total of 186 laboratory-confirmed patients with COVID-19 were included in this study. Among 186 patients, 48 (25.8%) were admitted to the ICU. Patients admitted to the ICU were older and had also more underlying comorbidities compared to patients admitted to the non-ICU ward (P<0.05). The levels of LDH, CRP, ALT, AST, and neutrophil count were higher in patients admitted to the ICU compared to patients who were not admitted to the ICU (P<0.05). Among the chest X-ray findings, consolidation was only a significant difference between patients admitted to the ICU and non-ICU patients (P<0.05). Among 48 patients admitted to the ICU, 6 patients (12.5%) were still in the ICU, 26 patients (54.1%) were discharged, and 16 patients (33.3%) died as of April 15, 2020. Our study showed that older age, male sex, and having underlying diseases are strongly associated with increased risk of severe disease and death in patients with COVID-19. Therefore, more attention should be paid to elderly male patients who have an underlying disease.