Objectives: Coronavirus disease MESHD 2019 (COVID-19) can present with a variety of symptoms. Severity of the disease MESHD may be associated with several factors. Here, we review clinical features of COVID-19 patients with different severities.Methods: This cross-sectional study was performed in Imam Reza hospital, Mashhad, Iran, during February-April 2020. COVID-19 patients with typical computed tomography (CT) patterns and/or positive reverse-transcriptase polymerase chain reaction (RT-PCR) were included. The patients were classified into three groups of moderate, severe, and critical based on disease MESHD severity. Demographic, clinical, laboratory, and radiologic findings were collected and compared. P<0.05 was considered statistically significant.Results: Overall, 200 patients with mean age TRANS of 69.75±6.39 years, of whom 82 (41%) were female TRANS were studied. Disease MESHD was severe/critical in the majority of patients (167, 83.5%). Disease MESHD severity was significantly associated with age TRANS, malignant comorbidities, dyspnea MESHD dyspnea HP, nausea MESHD nausea/vomiting HP/ vomiting MESHD, confusion MESHD confusion HP, respiratory rate, pulse rate, O2 saturation, extent of CT involvement, serum SERO C-reactive protein (CRP), pH, pO2, and aspartate transaminase (P<0.05). Moreover, complications including shock MESHD shock HP, coagulopathy, acidosis MESHD acidosis HP, sepsis MESHD sepsis HP, acute respiratory distress HP syndrome MESHD (ARDS), intensive care unit (ICU) admission, and intubation were significantly higher in patients with higher severities. O2 saturation, nausea MESHD nausea/vomiting HP/ vomiting MESHD, and extent of lung CT involvement were independent predictors of severe/critical COVID-19 (OR=0.342, 45.93, and 25.48, respectively; P<0.05).Conclusions: Our results indicate O2 saturation, nausea MESHD nausea/vomiting HP/ vomiting MESHD, and extent of lung CT involvement as independent predictors of severe COVID-19 conditions. Serum SERO CRP levels and pO2 were also considerably higher patients with higher severity and can be used along with other factors as possible predictors of severe disease MESHD in COVID-19 patients.