In spite of being a significant advance in the treatment of hydrocephalus, ventriculo-venous shunts cannot be considered a definitive solution. Among several disadvantages which have ariven from the widespread use of such techniques pulmonary embolism and fibrosis should be emphasized, the late consequences of which are unknown as yet. The search for new techniques and/or the improvement of old procedures thus seem quite justified. During the last four years we have employed a ventriculo-peritoneal shunt with valve in 110 patients, including 79 hydrocephalic children. The results have shown that physically both the valve shunts draining into the peritoneum or into the blood stream work similarly. In both instances reoperations have not been frequent, as it was the case when no valves were used in the peritoneal shunts. On the other hand, by using ventriculo-peritoneal shunts not only pulmonary microembolism is prevented but also infections involving the draining system are less severe and more easily controlled than those occurring in the ventriculo-atrial shunts.