Over a 2 1/2-year period, 34 patients underwent therapeutic external ventricular drainage with a valve-regulated system. The mean duration of drainage was 16 days. There was no incidence of ventricular infection, nor was there blockage of the ventricular catheter requiring revision. Eventually, 13 patients required ventriculoperitoneal shunts. All survivors remained free from complications after more than 6 months of follow-up. The system proved safe and reliable in patients requiring prolonged ventricular drainage.