Internal myiasis is a rare disease, which has not been reported in Korea, yet. This case report describes a patient with pneumonia associated with internal myiasis. She was 84-year old female who was admitted to the emergency department, Konyang University Hospital as a result of dyspnea and fever and a drowsy mental state. Approximately twenty fly maggots continuously crawled out from the nose at the third hospital day in the intensive care unit. These maggots were almost 7.2mm long and were identified as the genus lucilia belonging to the family Calliphoridae. In addition, a bronchial washing study showed eggs of the dipterous larvae. A lesion of this myiasis case might have been located in the respiratory system of patient. This case is the first internal myiasis of the respiratory system reported in Korea. This cases is discussed with a review of the relevant literature.