The aim of this study is to investigate the volumetric measurements of the maxillary sinus among Indonesian population through computed tomography (CT) scan semi-automated segmentation. This project collected 802 retrospective head CT scan archives from Department of Radiology, Hasan Sadikin Hospital, Bandung, Indonesia between 2019–2020. Patients with craniofacial anomalies/pathology fracture in proximity of the maxillary sinuses, and mediocre image quality were excluded from this study resulting only 97 CT scan archives (194 maxillary sinuses; 52 males; 45 females; age range 0–25 years old). Three-dimensional craniofacial structures were reconstructed and volumetric measurements of the maxillary sinus were computed through semi-automated segmentation using ITK-SNAP. This study recorded the initial phase of maxillary sinus pneumatization during infancy. The maxillary sinus developed until reaching the maximum of average maxillary sinus volume at 13,278.73 mm 3 in 16 to 20 years old group in which afterwards fell to 12,325.21 mm 3 . There was no difference found between right and left maxillary sinus volume. This study revealed that the pneumatization of maxillary sinus begin during infancy and climb until reaching the second decade of life, in which after that slowly decrease. Moreover, no difference between right and left maxillary sinus volume was detected. The volumetric dimension of maxillary sinus presented in this study may serve as the basis knowledge surgical intervention of maxillary sinus and its related structures.