Clinicians are challenged by the diagnostic dilemma that influenza cannot reliably be distinguished from other acute respiratory illnesses on the basis of clinical presentation alone [3] . Rapid viral antigen testing for diagnosis, which under ideal situations can yield results within 30 min, is not practical nor cost-effective in pandemic conditions [3] . Point-of-care ultrasound has been demonstrated to identify, in real-time, various pathologies of the lung, such as pneumonia, viral pneumonia, and acute respiratory distress syndrome (ARDS) [4] [5] [6] [7] [8] [9] [10] An algorithm for differentiating between various respiratory pathologies has been described ( Figure 3 ) [4] , and evidence-based recommendations regarding the use of point-of-care lung ultrasound have recently been published [11] . The use of lung ultrasound during the 2009 H1N1 influenza pandemic in adults has also been recently described [12] . We describe a prospective case series of children in whom clinicianperformed lung ultrasonography was used to differentiate between different respiratory pathologies and assessed interobserver agreement of these ultrasound findings during the initial onset and surge of the 2009 H1N1 pandemic (April to June 2009).