OBJECTIVE To explore the causes, predilection sites and treatment of nasal sinus mucoceles after hypophysectomy.METHODS The clinical data of 7 cases with nasal sinus mucoceles after hypophysectomy diagnosed and treated in our Department from Jan.1998 to Aug.2007 were retrospectively studied.RESULTS The mucoceles were located at ethmoid sinus in 2 cases,frontal sinus in 2 cases,frontal and ethmoid sinuses in 3 cases.All of the 7 cases underwent mucocelectomy under nasal endoscope or a combined endoscopic intranasal and extra-nasal approach.No recurrence was found after follow up for 1 to 3 years.CONCLUSION The causes of nasal sinus mucoceles after hypophysectomy are the change of the anatomic structure of nasal cavity after surgery.The stenosis,adhesion of middle nasal meatus or obstruction of the sinus ostium are found in all the patients.Intranasal endoscopic surgery or combined with extra-nasal approach is the first choice for nasal sinus mucoceles.