The psychostimulant methylphenidate has been previously shown to improve cognitive performance in both normal control volunteers and patient populations. In the present case study, the effects of methylphenidate on cognitive and behavioural function were examined in a single patient with idiopathic normal pressure hydrocephalus (NPH) who had undergone ventriculoperitoneal shunting. A double-blind placebo-controlled ABBA drug design was employed, with the administration of two different doses of methylphenidate followed by neuropsychological assessment on a number of psychometric tests and cognitive tasks drawn from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Methylphenidate produced a dose-dependent positive improvement in behavioural measures in the patient associated with a reduction in apathy. It also had a dose-independent enhancing effect on performance of a Spatial Recognition task. These findings require replication in a large sample of patients to determine whether methylphenidate may prove to be generally useful in enhancing cognition and reducing apathy in normal pressure hydrocephalus.