Background: The information on the difference in clinical characteristics between severe and non-severe cases is limited in some countries including Iran. The objective of this case series is to compare the clinical characteristics, radiologic features, and laboratory findings between COVID-19 severe cases who received the intensive care unit (ICU) care with non-severe cases who did not receive ICU care. Methods: In this retrospective cohort study, 186 laboratory-confirmed patients with COVID-19 diagnosed from 1 March 2020 to 30 March 2020 were investigated. Results: This study population included 186 hospitalized patients with confirmed COVID-19. The median age was 47 years, and 88 (47.31%) were female. Of these patients, 48 were admitted and transferred to ICU. Of 186 patients, 44.62% had medical comorbidities including hypertension and diabetes. The most common clinical manifestation were shortness of breath 86.56%, myalgia 74.19%, and headache. Higher neutrophil counts, CRP, and LDH as well as the lower levels of lymphocytes were the most important laboratory finding among COVID-19 patients. As of April 15, 2020, 33 were still hospitalized. A total of 116 patients (62.70 %) had been discharged, and 36 patients (19.94 %) had died. Of the 48 patients admitted to the ICU, 33.33% have died. Conclusion: In the present study, shortness of breath was the most common clinical symptom, and the mortality rate in patients admitted to the ICU was about 33%, indicating that about one-third of patients with severe illness who admitted to the ICU section died.