The cause of malfunction in 275 consecutive ventriculoperitoneal (VP) shunt revisions over an 8-year period were retrospectively analyzed. In all cases the shunt revised was a multicomponent (Holter) VP shunt. Disconnections in the system accounted for 41 (15%) of the malfunctions. The more distal the connection was from the ventricle, the higher the likelihood of disconnection. Furthermore, occipitally placed shunts had a significantly higher tendency to dislocate than frontally placed shunts.