Primary rhabdomyosarcoma is a rare entity. To date, only 29 cases have been reported in the world literature. The current article presents another case of this disease, in which a 3-year-old boy was referred to our service with a one-week history of productive cough and fever. Imaging studies revealed a huge mass on the right lung as well as plural effusion. He underwent a right posterolateral thoracotomy and lobectomy. Pathologic studies revealed a primary pulmonary rhabdomyosarcoma of embryonic type. He has no other symptoms of disease on a 6-month follow-up.