Thirteen patients aged 1 to 59 years hospitalized for diabetes insipidus (DI) were investigated by computed tomography (CT). Apart from one craniopharyngioma, CT revealed in 8 out of 12 cases several modifications in the hypothalamic – pituitary region. In this group, CT demonstrated a small, round, isodense mass in the chiasmatic cistern that enhanced after contrast medium injection. Coronal and sagittal reconstructions helped pinpoint the lesion in the infundibulum and pituitary stalk, and, in one case, in the supraoptic nuclei. These findings, and the noninvasiveness of CT, make this technique one of the most accurate means of radiological investigation of DI and also of determining the efficacy of therapy.