We describe a case of neuroleptic malignant syndrome in a female patient affected with schizophrenia who has been treated with neuroleptics for thirty years. Six months prior to the occurrence of this disorder neither the kind of psychotropic drug nor the dosage were changed. The signs of dehydration already dominated her symptoms during the first days, so we stress its possible role in the genesis of this syndrome without neglecting the theory of massive blockade of dopamine receptors as a primary pathophysiological mechanism.