Abstract Introduction The aim of the study was to evaluate the results of surgery to remove huge mediastinal masses and their pathology. Surgical resection was chosen for accurate diagnosis and treatment of the huge mediastinal masses extending into the pleural cavity. Methods Records were reviewed for eight patients who had the diagnosis of huge benign mediastinal masses and who underwent operation; details of the patients and operations were recorded. Results Mean age was 34.5 (range 22 to 44) years, and male-to-female ratio was 2:6. Computed tomography and magnetic resonance imaging (MRI) were used to evaluate the location and extent of the abnormality and to characterize the tissue components of the mass. Most of the tumors were located in the posterior mediastinum. The most frequent presenting symptom was exertional dyspnea. The majority of cases underwent posterolateral thoracotomy, and complete resection was possible in seven patients. Partial resection could only be performed in one. The mean diameter of the resected masses was 15 × 10 cm. Histopathologic examination revealed 3 neurogenic tumors, 2 teratomas, 1 thymolipoma, and 1 ectopic thyroid, and 1 hemangioma. Minor complication was seen in two cases. Conclusion The presurgical thoracic MRI provided correct diagnosis along with radiologic characterization and topography. Surgery must be the preferred treatment in huge benign mediastinal masses.