The authors describe a very rare malignant neuroleptic syndrome in a 9-year-old girl as a potential fatal complication of neuroleptic treatment. The pathogenesis involves a block of dopamine D2-receptors in the nigrostriate area and the hypothalamus. The main characteristics include extrapyramidal syndrome, hyperther- mia, quantitative and qualitative disorders of consciousness and behaviour, impaired function of the vegetative nervous system, hypoxaemia, respiratory and metabolic acidosis, hyperkaliaemia, myoglobinuria, elevated values of creatine kinase and transaminases, leucocytosis and on the EEG mild diffuse changes. Risk factors leading to the development of the syndrome are organic cerebral changes, malnutrition and dehydration, physical exhaustion, stress, high environmental temperature, large doses of neuroleptics and sudden increase or decrease of the dose. For the diagnosis criteria according to DSM-IV are used. For control of the condition it i s essential to discontinue neuroleptics, intense cooling of the patient with ice packs, administration of peripheral myorelaxing agents (Dantrolen), dopamine agonists, anticholinergic agents and benzodiazepines. Electr oconvulsive treatment is also used. Recently Biston is recommended. 20 - 30% of the affected patients die.

        Key words: complications of neuroleptic treatment, malignant neuroleptic syndrome, block of dopamine