Objective: Understanding the natural course of COVID-19 and determining its clinical findings are essential for early diagnosis and treatment. In this study, we aimed to investigate clinical and laboratory characteristics of cases followed with a diagnosis of COVID-19 in Selçuk University Faculty of Medicine Department of Infectious Diseases and Clinical Microbiology. Methods: Among patients followed with a diagnosis of pos-sible/definitive COVID-19, those with a positive SARS-CoV-2 RT-PCR test were evaluated retrospectively in terms of their clin-ical, laboratory and thorax computed tomography (CT) data. Results: Among 407 patients followed with a diagnosis of pos-sible/definitive COVID-19, 149 (36.6%) were SARS-CoV-2 RT-PCR test-positive. 82 (55%) of the patients were female and 67 (45%) were male. Mean age was 49.3±7.6 years. 11 (7.4%) were health care workers. While the most common symptom was cough with 46.3%, fever was observed in 29.5%, sore throat in 27.5% and malaise in 26.8% of the patients. 94 (63.1%) of the patients had underlying diseases. Hypertension and diabetes mellitus were the most common underlying disease. Laboratory findings were leukopenia in 12 (8.1%), lymphopenia in 34 (22.8%), throm-bocytopenia in 24 (16.1%), elevated D-dimer levels in 43 (28.9%), elevated lactate dehydrogenase levels in 73 (49%), and elevated C-reactive protein (CRP) levels in 45 (30.2%) patients. While 71 (47.6%) of the patients had normal thorax CT, 43 (28.9%) had mild pneumonia, and 35 (23.5%) moderate pneumonia. D-dimer and CRP levels were higher in those with pneumonia than those without pneumonia (p=0.001 and p=0.001, respectively). As the pneumonia level increased, the increase of D-dimer and CRP levels became evident (p=0.003 and p=0.001, respectively). Conclusions: The clinical course of COVID-19 patients varies. It is noteworthy that there is a positive correlation between the severity of pneumonia and the increase in D-dimer and CRP levels in COVID-19. Klimik Dergisi. 2020; 33(2): 122-7.