Abstract Background The aim of this study was to evaluate regional postoperative preserved pulmonary function (PPPF) and three‐dimensional (3D) volumetric changes according to the number of resected subsegments and investigate the factors that most affected pre‐/post PPPF. Methods Patients who underwent thoracoscopic lobectomy (n = 73), and segmentectomy (n = 87) were eligible for inclusion in the study. They were classified according to the number of resected subsegments which ranged from 1 to 10. The percentage of pre‐/postoperative forced expiratory volume in 1 s (FEV1) was used for comparison. Furthermore, lung volumetric changes were calculated using 3D computed tomography (CT) volumetry. Results The percentage of pre‐/postoperative EFV1 between 4 and 5–7 and between 5–7 and 10 were significant (p = 0.03 and p