All morphologic aspects of neoplastic and non neoplastic masses, arising from the diencephalic-hypothalamic region are discussed in this paper. We describe the densitometric characteristics on CT scan and the MRI appearance of masses affecting this region, both of benign lesions and malignant neoplastic masses. We describe separately masses arising from within the III ventricle and those of extraventricular origin and all semiotic findings of neuroradiological techniques of computed imaging.