Post-operative problems of hydrocephalus which occur in a high percentage of intraventricular tumours are infrequently discussed. Our experience, however, showed many problems in the treatment of hydrocephalus associated with supratentorial intraventricular tumours. In a series of 40 supratentorial intraventricular tumours different types of management were used and reviewed retrospectively. It is concluded that certain types of management are disadvantageous, like primary shunt insertion. As a result the recommended form of treatment is: primary temporary external CSF-drainage followed by tumour surgery. Post-operative assessment of ventricular compartments and tolerance of drainage withdrawal. Shunt insertion only if compartmentilization or drainage dependency were manifest.