Fetal lung interstitial tumor (FLIT) is a rare primary lung mass in neonates. Classical incisions, such as posterolateral thoracotomy or median sternotomy, do not provide optimal exposure of the operative field for the resection of pediatric thoracic giant tumors. Herein, we report a rare case of a FLIT in a full-term male neonate, with complete resection achieved using a hemi-clamshell approach, which provided the required visualization of the operative field. The neonate was transferred to our hospital because of mild respiratory distress, which developed 18-hour after normal vaginal delivery. A mass in his right chest, without a midline shift, was observed on chest radiographs. Computed tomography showed a well-circumscribed solid anterior cervicothoracic mass, with a uniform density and no apparent cysts, diagnosed as a primary thoracic giant tumor. Once the patient was clinically stabilized, we proceeded with right upper lobectomy, using a hemi-clamshell approach, full sternotomy, and anterolateral thoracotomy, on postnatal day 22. Histopathologic examination revealed an 8.5 × 6.5 × 4.0 cm solid mass within the right upper lobe, which was diagnosed as a FLIT. His postoperative recovery was uneventful. The patient was followed up for 1 year, with no complaints or symptoms and no postoperative shoulder dysfunction. Gross total resection of primary thoracic giant tumors can be accomplished in neonates with optimal exposure of the chest cavity using a hemi-clamshell approach.