OBJECTIVES: Recent studies suggest that lung ultrasound is a good, radiation-free alternative to chest radiography in children with pneumonia. We investigated how bedside lung ultrasound performed by a pediatric resident compared with chest radiography in children with suspected pneumonia. METHODS: This was a prospective study comparing bedside lung ultrasound to chest radiography as the reference standard. Children aged 0 to 15 years with suspected pneumonia at a pediatric emergency department were included and underwent chest radiography and lung ultrasound. A pediatric resident with minimal practical ultrasound experience and with no access to supervision performed the bedside lung ultrasound and was blinded to the patientsʼ medical evaluation. RESULTS: A total of 82 children underwent both chest radiography and lung ultrasound (57% boys; median [interquartile range] age, 1.5 [1.1–2.5] years). The lung ultrasound took 7 to 20 minutes to perform, and 10% were of suboptimal quality due to an uneasy child. The prevalence of consolidations by chest radiography was 50%. Lung ultrasound had a sensitivity of 40% (95% confidence interval [CI], 30%–51%), specificity of 91% (95% CI, 83%–96%), positive likelihood ratio of 4.71 (95% CI, 2.21–10.04), and negative likelihood ratio of 0.65 (95% CI, 0.54–0.79). CONCLUSIONS: Bedside lung ultrasound is a useful tool, with a good specificity, to find lung consolidations in children even when the sonologist has minimal practical ultrasound experience and no access to supervision. We suggest the use of bedside lung ultrasound as a diagnostic tool in children with suspected pneumonia.