Three hundred and twenty five cases of hormonally inactive giant pituitary tumors, having their maximum dimension of more than 3 cm, treated surgically in our neurosurgical department from the year 1995 to November 2008 were analyzed. Depending on the extensions and the nature of their meningeal coverings these tumors were divided into four grades. Average duration of follow-up was thirty-six months.There were 135 giant pituitary tumors, which remained within the confines of sellar dura and under the diaphragma sellae and did not enter into the compartment of cavernous sinus (Grade I). Transgression of the medial wall and invasion into the compartment of the cavernous sinus (Grade II) was seen in 109 cases. Elevation of the dura of the superior wall or roof of the cavernous sinus (Grade III) was observed in 59 cases.Supradiaphragmatic- subarachnoid extension (Grade IV) was seen in 22 patients.Radical surgery by a transsphenoidal route is indicated and possible in Grade I-III pituitary tumors. Such a strategy offered a reasonable opportunity for recovery in vision and a satisfactory post-operative and long-term outcome. Biopsy of the tumor followed by radiotherapy could be suitable for Grade IV pituitary tumors. 

Key Words:Giant pituitary tumors, cavernous sinus,diaphragma sella, dura.