Osteonecrosis is a debilitating bone disease affecting adults who have recovered from severe acute respiratory syndrome in Hong Kong and China, but there are no data on its prevalence in children. We report 5 children with magnetic resonance imaging evidence of osteonecrosis. In view of the high prevalence and asymptomatic presentation of osteonecrosis, we suggest magnetic resonance imaging screening for osteonecrosis in children with severe acute respiratory syndrome.