Thymoma is an epithelial neoplasm of the thymus, which commonly lies in the anterior mediastinum. Unusually it can be found in other locations as well. Ectopic thymoma rarely presents as an intrathoracic tumor. We report a case of ectopic thymoma presenting as a giant right intrathoracic tumor, the patient was 51-year-old, and who was presented with heaviness in chest and breathlessness. Detailed investigation including chest computed tomography scan revealed a well-defined large solid tumor in the right thoracic cavity, in this case, immunohistochemical analysis demonstrated a thymome AB. The tumor was metastatic to the lung. Patient received a neoadjuvant chemotherapy, with favorable evolution.