Anterior mediastinal teratomas are rare germ cell tumors. We report a case of such rare tumor in a young adult male of 21 yrs old who presented with persistent cough of one and half month duration. Computed tomography of the chest confirmed the diagnosis as anterior mediastinal teratoma. Patient underwent a right anterolateral thoracotomy. Intraoperatively there was a large mass in the anterior mediastinum extending to right hemithorax. The mass was compressing the great vessels, adherent to chest wall, pericardium, and lung. Complete excision of the mass done. Patient underwent uneventful recovery. Histopathology reported as benign cystic teratoma.