Abstract Coronavirus disease 2019 (COVID-19) with acute respiratory failure (ARF) has a high mortality rate. This study aimed to investigate the vital signs and work of breathing parameters in COVID-19 pneumonia patients to predict ARF. We predicted the risk of acute respiratory distress syndrome (ARDS) in COVID-19 patients within 72 hours of admission to the emergency department (ED) and determined cut-off values. We performed an observational prospective cohort study at the tertiary referral Persahabatan Hospital in Jakarta, Indonesia, from July to December 2020. The vital signs were as follows: of respiratory rate (RR), heart rate (HR), pulse oxygen saturation (SpO2), mean arterial pressure (MAP), and axillary body temperature. The work of breathing, which was indicated by nasal flaring and the contraction of the sternocleidomastoid and abdominal muscles, was assessed one hour after a triage …