Coronaviruses have been demonstrated to contribute substantially to respiratory tract infections among the child population. Though infected children commonly present mild upper airway symptoms, in high-risk patients with underlying conditions, particularly in immunocompromised children these pathogens may lead to severe lung infection and extrapulmonary disorders. In this paper, we provide the first report of the case of a 15-month-old child with severe combined immunodeficiency and coronavirus HKU1-related pneumonia with fatal respiratory distress syndrome. ยฉ 2012 John Wiley & Sons Ltd.