The Authors report their experience in using water-soluble contrast medium in ventriculographies having carried out 102 ventriculographies partly with Dimer X and partly with "Uromiro 300". Their conclusions are practically similar to those already reported by the many Authors who have written on this subject: 1) facility of examination particularly in urgent cases; 2) excellent neuroradiological definition of the cases; 3) possibility of obtaining a selective ventriculography; 4) indication especially in space-occupying lesions of the posterior cranial contrast medium; 6) possibility of reducing complication rate by carefully carrying out the examination and by avoiding the use of excessive quantities of contrast. In particular the Authors describe some useful methods for obtaining better technical results from the examination and reducing the complication rate.