Thymomas are usually benign tumors and are most often found in the anterior mediastinum. We report a rare case of a giant tumor in the right hemithorax that originated in the thymus. The tumor was 15x8 cm and histology revealed a type AB thymoma. The tumor was removed and the patient is doing well and is without symptoms two years after the operation. Key words: Thymoma, abdominal pain, giant tumor, mediastinum.