In this study, we report a familial cluster of cases which included five patients and two close contacts who were confirmed to have coronavirus disease 2019 (COVID-19). These participants had received real-time reverse transcription-polymerase chain reaction (RT-PCR) and chest X-rays (CXRs) before diagnosis. The follow-up CXRs of three patients in the family showed significant progression, with COVID-19 pneumonia, clinically worsening in a short period of time. Therefore, the results of follow-up CXRs in the short-term may be an adjunctive diagnostic method for COVID-19 disease diagnosis and its progression. Key Words: Chest X-ray, COVID-19, RT-PCR, Familial clustering.