The coronavirus disease 2019 (COVID-19) outbreak that started in Wuhan, Hubei province, China in December 2019 has now extended across the globe with >100,000 cases and 3,000 deaths reported in 93 countries as of 7 March 2020. We report a case of COVID-19 infection in a 64-year-old man who developed rapidly worsening respiratory failure and acute respiratory distress syndrome (ARDS) that required intubation. As the clinical spectrum of COVID-19 ranges widely from mild illness to ARDS with a high risk of mortality, there is a need for more research to identify early markers of disease severity. Current evidence suggests that patients with advanced age, pre-existing comorbidities or dyspnoea should be closely monitored, especially at 1-2 weeks after symptom onset. It remains to be seen if laboratory findings such as lymphopenia or elevated lactate dehydrogenase may serve as early surrogates for critical illness or markers of disease recovery. Management of ARDS in COVID-19 remains supportive while we await results of drug trials. More studies are needed to understand the incidence and outcomes of ARDS and critical illness from COVID-19, which will be important for critical care management and resource planning.