Three cases of parasellar involvement of meningioma are reported with tomography through the sphenoid bone. A smooth tumor bulge into the sphenoid sinus together with hyperostosis was demonstrated in each instance. The combination of hyperostotic bone with smooth tumor bulge is felt to be diagnostic of parasellar meningioma. In patients with the clinical picture suggesting the possibility of sphenoid ridge or middle fossa meningioma, and/or those demonstrating hyperostosis or sphenoid sinus opacification of questionable significance on plain skull roentgenograms, appropriate tomography should be carried out in an attempt to demonstrate the above combination of roentgen changes.