Background: Chest radiographs (CXRs) are frequently performed to evaluate pneumonia in children. The aim of this study was to analyze the CXR findings of childhood Mycoplasma pneumoniae pneumonia and its correlation with clinical manifestations. Methods: This study includes 465 children diagnosed with M. pneumoniae pneumonia between 2000 and 2015 at the Seoul National University Children’s Hospital. Clinical manifestations were reviewed and CXRs were interpreted. The CXRs were categorized as normal, consolidation (lobar consolidation or patchy consolidation), or other infiltrate (nodular opacity or bilateral parahilar infiltration). The pediatricians and radiologists were all blinded to both results. Results: CXRs performed at diagnosis were abnormal in 438 (94.1%) children. Patchy consolidation (39.3%) and bilateral parahilar infiltration (28.5%) were the two most common findings, followed by nodular opacity (18.5%) and lobar consolidation (13.7%). Lobar consolidation frequently accompanied parapneumonic effusions (78.3%, P 0.001) as well as atelectasis (18.3%, P = 0.059). Lobar consolidation was more frequent in children ≥5 years compared with children 2 years (16.9% vs. 2.4%, P = 0.034) and this difference was similar for patchy consolidation (45.3% vs. 21.4%, P = 0.007). Bilateral parahilar peribronchial infiltration was most commonly observed in children 2 years (59.5%, P 0.001). CXR consolidation was associated with higher rate of fever (98.7%, P 0.001), hypoxemia (24.2%, P = 0.036), tachypnea (56.0%, P = 0.005), decreased breath sound (40.5%, P 0.001), extrapulmonary manifestations (37.4%, P 0.001), and also longer duration of fever (11 days, P 0.001) and macrolide treatment (14 days, P 0.001) compared to other infiltrate CXRs. Macrolide was less frequently prescribed in children with other infiltrate than those with consolidation (85.1% vs. 91.8%, P = 0.029). Children with other infiltrate on CXRs frequently presented with chest retraction (14.7%, P = 0.017), crackles (66.0%, P 0.001), and wheezing (14.1%, P = 0.001). Conclusions: CXR findings of children with M. pneumoniae pneumonia explain the clinical findings and the course of the infection; consolidation on CXRs are frequently observed in children ≥5 years and accompanied longer fever duration with more parapneumonic effusions requiring longer treatment.