Fifty four patients with hydrocephalus treated with surgical derivations were evaluated in retrospect. The total number of derivations made to this group was 76. Initially 30 valves were from VA type and the remaining 24 from VP type, but reintervention was needed in 15 and 11 respectively. The etiology of hydrocephalus was congenital in 61%; infectious, in 24%; tumoral, in 8%, and consequence of a traumatism, in 7%. Twenty-three patients (42%) followed a good evolution without any complication as much immediately as later. The other 31 patients (57%) have had some kind of postoperative complication. In 26 patients (48%) the valve had to be removed. The main causes were infection in 10 cases (18%) and obstruction in 14 cases (25%). Usually the staphylococcus was the infectious agent. Ten of the patients died (18%), eight of them by a complication directly related to the shunt.