A Case of foreign body in ethmoid sinus was observed in a 5-year-old Korean boy. A pencil-lead had been introduced into the ethmoid cell and frontal sinus of the child which resulted in formation of an organizing abscess in the above mentioned area. The complete removal of the lesion cleared up the abnormal denisities of the ethmoid and frontal sinus noted in the X-ray films of skull and Caldwell view.