Introduction: Despite the existence of published guidelines for more than a decade, there is still a substantial variation in the management of idiopathic normal pressure hydrocephalus due to its diagnostic and therapeutic complexity. Development: The diagnostic and therapeutic protocol for the management of idiopathic normal pressure hydrocephalus in use at the Department of Neurosurgery of the University Hospital Marques de Valdecilla is presented. The diagnostic process includes neuropsychological testing, phase contrast cine MRI, urodynamic evaluation, continuous intracranial pressure monitoring, cerebrospinal fluid hydrodynamics by means of lumbar infusion testing, and intra-abdominal pressure measurement. A patient is considered a surgical candidate if any of the following criteria is met: mean intracranial pressure >15 mmHg, or B-waves present in >10% of overnight recording; pressure-volume index4.5 mmHg/ml/min in bolus infusion test; R-out, >12 mmHg/ml/min, intracranial pressure >22 mmHg, or high amplitude B-waves in the steady-state of the continuous rate infusion test; or a clinical response to high-volume cerebrospinal fluid withdrawal. Conclusions: The implementation of a diagnostic and therapeutic protocol for idiopathic normal pressure hydrocephalus management could improve various aspects of patient care. It could reduce variability in clinical practice, optimise the use of health resources, and help in identifying scientific uncertainty areas, in order to direct research efforts in a more appropriate way. (c) 2016 Sociedad Espanola de Neurocirugia. Published by Elsevier Espana, S.L.U. All rights reserved.