Background/Purpose: This study quantified the lung volume development of pectus excavatum (PE) patients using chest computed tomography (CT) 3-dimensional volumetric reconstructions. The technique permits current and retrospective analyses of data from different institutions. Patients and Methods: We analyzed the records of PE patients who underwent chest CT preoperatively between 2005 and 2009 at 3 institutions. All patients were Chinese. Awindow of -992 to -198 Hounsfield units was chosen for calculating the CT total lung volume (TLV). The data were compared with the data for 73 microtia and other chest-wall tumor patients studied during the same period as a control group. Results: In total, 377 PE patients with Haller pectus index (PI) of at least 3.2 were identified for this study. Compared with the reported TLV data for 1050 healthy children and our control group, we found little evidence of a decreased TLV in PE patients at any age for either sex. The mean PI did not change significantly between the ages of 3 and 27 years. The PI was inversely correlated with the TLV (P <.001). Conclusion: Our cross-sectional study provides evidence that the TLV of PE patients is within the reference range in children and adolescents. (C) 2010 Elsevier Inc. All rights reserved.