ObjectiveTo summarize experience with intraoperative real time type-B ultrasound in precise delimitation of the supratentorial lesions.MethodsFifty intraoperative type-B ultrasound studies were carried out in patients with supratentorial lesions(35 glioma,8 cavernous hemangiomas,3 meningiomas,3 metastatic tumors and one aneurysm).ResultsIntraoperative type-B ultrasound couldaccurately localize the supratentorial lesions and assist in microsurgical resecting of the supratentorial lesions.Total resection in 30 glioma patients andsubtotal resection in 5.The precise delimitation of the other lesions including 8 cavernous hemangiomas, 3 meningiomas, 3 metastatic tumors and one aneurysm, which assisted by intraoperative real time type-B ultrasound, were also successfully performed.There were no new postoperatively neurological deficits, no operative complications, no mortality and no intraoperative ultrasound-related complications in these patients.ConclusionsThe intraoperative ultrasound is a very useful tool in intraoperative real time localization and delineation of lesions and planning various stages of supratentorial lesions resection.It assisted neurosurgeons in maximizing resections of supratentorial lesions and preserving the neurological function in a safe manner.It is an easy, convenient, reliable, widely available and cost-effective tool.