Encephalic ventricles were evaluated by CT and US in normal subjects and in patients suffering of meningitis. The biometry and statistical analyses were performed observing the ventricular index (VI%), and the diameters of the frontal and temporal horns of the lateral ventricle, and the diameters of the III and IV ventricles. Comparing the two diagnostic methods the coefficient of correlation was high for the lateral ventricle diameter (r=0.94) and for the VI (0.85). The sensitivity of the US was better than the CT in the observation of the temporal horn diameter. The US, because it high accuracy, it low cost and the possibility to be a portable equipment, is a useful method to investigate cerebral ventricles in infants