Idiopathic normal pressure hydrocephalus (INPH) is a syndrome that can be characterised by the following triad of symptoms: gait disturbances, cognitive impairment and urinary incontinence. The suspected diagnosis can be confirmed by cerebral ventriculomegaly and by a positive result of cerebrospinal fluid drainage. The frequent occurrence of comorbidity and a unflinching firm belief in the significance of the triad of clinical symptoms can hinder a correct diagnosis, leading to a delay in treatment and a poor prognosis. To illustrate this thesis we describe a 77-year-old patient with INPH and severe neuropsychiatric comorbidity.