['Ventriculo-peritoneal shunting is the most commonly used method for the treatment of paediatric hydrocephalus. The programmable valve with the ability to adjust the opening pressure non-invasively has made it easier to find exactly the right opening pressure for each child and reduce the risk of over- or under-drainage. The aim of this investigation was to study our clinical experience with the adult Codman Hakim programmable valve in children, with reference to complications and economic impact.', 'A seven-year retrospective study of 122 hydrocephalic children (aged from children born prematurely to 15 years old) shunted with the adult Codman Hakim programmable valve was performed.', 'The programmable valve was the first shunt in 76 children and in 14 after prior ventricular drainage. The remaining 46 had different non-programmable systems as their first shunt. The most common reason for changing to a programmable valve was over-drainage. With the programmable valve, catheter-related complications, e.g. proximal (36%) or distal obstructions (30%), were the main reasons for surgical revision. Non-invasive pressure adjustment was performed in 73% of the children. Among the children with the programmable valve as their first shunt, 57 (75%) were adjusted, 12 (21%) had severe symptoms of over-drainage and would have required urgent surgical change of the valve if it had not been adjustable. A resetting of the opening pressure after MRI was found in 38% and accidental resetting occurred in 4%. Programmable valves are about twice as expensive as non-programmable valves. We estimated the increased cost of the valve and compared it with the savings from a reduction in the number of re-operations. The total cost for the programmable valve (as the primary shunt) in our study was less than that for expected re-operations due to over- or under-drainage when using non-programmable valves.'] Is the programmable adult Codman Hakim valve useful even in very small children with hydrocephalus . A 7-year retrospective study with special focus on cost/benefit analysis?