We reviewed our experience on postoperative lobar torsion. From January 1994 to December 2003, 1002 patients underwent lobectomy for lung cancer. Two (0.2%) patients with postoperative lobar torsion required surgical reintervention. The first case was that of a 79-year-old man who underwent left lower lobectomy for pulmonary adenocarcinoma. Based on the postoperative course, lobar torsion was highly suspected with progressive respiratory dysfunction and the chest X-ray showed complete opacification of the residual lobe. Rethoracotomy was performed on postoperative day 4. The left upper lobe was rotated clockwise, and completion pneumonectomy was carried out. The patient died 16 days after the second surgery because of respiratory failure due to severe pneumonia. The second case was that of a 24-year-old man with a diagnosis of metastatic lung cancer in the right upper lobe arising from pharyngeal cancer. The patient underwent right upper lobectomy and developed hemoptysis and persistent high fever. A chest computed tomography (CT) and bronchoscopy findings revealed lobar torsion of the middle lobe, and a reoperation was performed. The middle lobe was resected and the patient was discharged 8 days after the rethoracotomy. Pulmonary lobar torsion poses a difficult diagnostic dilemma in the early postoperative period after the pulmonary resection. Since late reoperation for postoperative lobar torsion sometimes results in poor prognosis, careful observation with bronchial fiberscopy as well as chest radiography is necessary for accurate diagnosis. Rethoracotomy should be carried out without any delay in cases of lobar torsion following pulmonary resection.