The authors investigated MR capabilities in evaluating the neoplasms of the base of tongue. Thirty patients were examined. The images were obtained--at INI, Grottaferrata, Rome--using a 1.5 T superconductive Gyroscan unit by Philips. On T2-weighted images, the neoplasms were always hyperintense; in 10 patients edema could be distinguished from neoplasm. On T1-weighted scans the tumor exhibited the same signal intensity as the tongue muscle in 4 patients, while in the extant 26 cases it was hypointense. This pattern proved to be aspecific and could not be correlated with a specific histology. In 3 clinically symptomatic patients, MR imaging diagnosed the invasion of the internal pterigoid muscle. MR capabilities in identifying swollen lymph nodes was also evaluated on the basis of the signal intensities of the latter, as well as on their size. The authors' conclusion is that MR imaging is to be considered the method of choice in the staging of tumors at the base of tongue thanks to its high contrast resolution and multiplanar capabilities.