Objective This study was performed to investigate the clinical characteristics of patients with coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods We analyzed the electronic medical records of 405 hospitalized patients with laboratory-confirmed COVID-19 in the Third Hospital of Wuhan. Results The patients' median age was 56 years, 54.1% were female, 11.4% had a history of smoking, and 10.6% had a history of drinking. All cases of COVID-19 were community-acquired. Fever (76.8%) and cough (53.3%) were the most common clinical manifestations, and circulatory system diseases were the most common comorbidities. Gastrointestinal symptoms were present in 61.2% of the patients, and 2.9% of the patients were asymptomatic. Computed tomography showed ground-glass opacities in most patients (72.6%) and consolidation in 30.9%. Lymphopenia (72.3%) and hypoproteinemia (71.6%) were observed in most patients. About 20% of patients had abnormal liver function. Patients with severe disease had significantly more prominent laboratory abnormalities, including an abnormal lymphocyte count and abnormal C-reactive protein, procalcitonin, alanine aminotransferase, aspartate aminotransferase, D-dimer, and albumin levels. Conclusion SARS-CoV-2 causes a variety of severe respiratory illnesses similar to those caused by SARS-CoV-1. Older age, chronic comorbidities, and laboratory abnormalities are associated with disease severity.