Materials and Methods This is a case series of the 28 patients with confirmed COVID-19 in Korea as of February 14th, 2020. To obtain demographic, epidemiological, and early clinical information, COVID-19 reporting and surveillance data from Korea Centers for Disease Control and Prevention (KCDC), and the 28 case reports of the epidemiological investigation conducted by KCDC rapid response team was utilized. Patient age was provided on the date of diagnosis, and key indicators such as estimated duration of exposure, date of onset of symptoms, and route of transmission were identified by an epidemiological investigator who participated in the field investigation and the epidemiological investigation team at KCDC headquarters. The incubation period was estimated based on the estimated exposure date and the date of symptom onset. However, it must be noted that the data presented in this study may change depending on the results of further epidemiological investigation.