Normal pressure hydrocephalus (NPH) is characterized by gait disturbance, dementia and/or urinary incontinence associated with dilation of ventricular system with normal opening cerebrospinal fluid pressure. Wide scientifical evidence confirms association between NPH and psychiatric symptoms. We selected 35 patients with idiopathic normal pressure hydrocephalus from January 2010 to January 2012 in a Brazilian tertiary hospital and performed a formal psychiatric evaluation to identify psychiatric disorders. Psychiatric disorders were present in 71% of these patients, especially anxiety, depression and psychotic syndromes. NPH patients may develop symptoms with frontal dominance, such as personality changes, anxiety, depression, psychotic syndromes, obsessive compulsive disorder, Othello syndrome; shoplifting and mania. Unusual appearances of NPH symptoms may hinder early diagnosis and consequently proper treatment.Keywords: normal pressure hydrocephalus, psychiatry, symptoms. RESUMO A hidrocefalia de pressão normal (HPN) é caracterizada por distúrbios da marcha, demência e/ou incontinência urinária associada com dilatação do sistema ventricular e pressão de abertura do líquido cefalorraquidiano normal. Evidências científicas confirmam associação entre HPN e sintomas psiquiátricos. Foram selecionados 35 pacientes com hidrocefalia de pressão normal idiopática, de janeiro de 2010 a janeiro de 2012 em um hospital terciário brasileiro e realizada uma avaliação psiquiátrica formal para identificar transtornos psiquiátricos. Transtornos psiquiátricos foram detectados em 71% dos pacientes, principalmente depressão, ansiedade e síndromes psicóticas. Pacientes com HPN podem desenvolver sintomas com predomínio frontal, tais como mudanças de personalidade, ansiedade, depressão, síndromes psicóticas, transtorno obsessivo compulsivo, síndrome de Otelo, furtos e mania. Sintomas incomuns de HPN podem dificultar o diagnóstico precoce e o tratamento adequado.Palavras-chave: hidrocefalia de pressão normal, sintomas, psiquiatria.Normal pressure hydrocephalus (NPH) is a syndrome characterized by gait disturbance, dementia and urinary incontinence plus dilation of ventricular system due to disturbance of cerebrospinal fluid (CSF) circulation with normal CSF pressure 1,2,3,4,5,6 . Dilated ventricles theoretically impair perfusion in ventricular walls, generating hypoperfusional states especially in frontal lobes, basal ganglia and thalamus, thus resulting classic symptomatology 7 . NPH can present in two forms: primary (also known as idiopathic), when there are no causative disorders and secondary, where other disorders such as trauma, infection and hemorrhage are putative causes for hydrocephalus 1,2,3,4,5,6 . Idiopathic NPH (INPH) is associated with communicating hydrocephalus (as demonstrated by brain CT or MRI) and CSF pressure within normal range (7-24 cm H2O) 1,2,3,4,5,6 . With improvements in quality of life and subsequent increase in life expectancy, it is expected that a greater number of elderly individuals will suffe...