In our experience, neoplastic lesions of the floor of the third ventricle are frequently responsible for neurologic and dysendocrine symptoms. Ct scan and MR imaging are the most reliable techniques of neuroimaging in the diagnostic study of neoplastic masses affecting this region. In this work, CT and MR appearance of lesions of the III ventricle floor are discussed with the aim of contributing to the differential diagnosis of neoplasms and their surgical and medical management.