Background: Conventional chest X-ray (chest X-ray) in Dharmais Cancer Hospital emergency room (ER) is still the primary modality to diagnose patients with cancer with dyspnoea complaints. Chest X-ray was also carried out to screen inpatients at the Dharmais Cancer Hospital ER at the beginning of the COVID-19 pandemic in Indonesia. It was essential because patients in the Dharmais Cancer Hospital ER were patients with cancer, with low immunity and a high risk of being exposed to various infections. Thus, the purpose of this study was to determine the characteristics of chest X-rays in patients with cancer at the Dharmais Cancer Hospital ER during the COVID-19 pandemic in February-May 2020. Methods: This was a descriptive study. The population involved was all patients at the Dharmais Cancer Hospital ER who received chest X-ray support, with the inclusion criteria for diagnosing lung cancer, breast cancer, cervical cancer, colorectal cancer, and blood cancer (Leukemia) from February to May 2020. Data analysis employed univariate analysis by utilizing tables and graphs in presenting the data. Results: 289 samples met the research criteria. The highest visits were patients with breast cancer (41.2%). The most common thoracic images were pleural effusion (34.3%), followed by bronchopneumonia (31.1%), normal lung (16.6%), lung mass (7.6%), pneumonia (5.2%), and others (5.2%), consisting of atelectasis, bronchitis, fibrosis/chronic pulmonary process, pulmonary emphysema, cardiomegaly, and specific process. Besides, the chest x-ray bronchopneumonia was 31.1% (90 samples), accompanied by pleural effusion of 44.4%. From the chest X-ray, pleural effusions were 34.3% (99 samples), with lung cancer being the most common with pleural effusions (48.4%). Conclusions: More than 80% of chest x-ray performed in the ER are abnormal. Also, breast cancer is the highest in the Dharmais Cancer Hospital ER cases, with the highest chest x-ray of pleural effusion.