SUMMARYNeuroleptic malignant syndrome (NMS) is a rare and potentially fatal adverse reaction to drugs. In psychiatric practice, it is mainly associated with antipsychotics. The classic presentation is that of hyperpyrexia, muscle rigidity, mental state changes and autonomic instability. Subtle forms are difficult to recognise owing to symptom overlap with other conditions. This article discusses the clinical presentation of the syndrome, its differential diagnosis and use of supportive care, medication and electroconvulsive therapy in its treatment. It also explores prevention of NMS and reinstatement of treatment after an episode. It is stressed that all but the mildest forms of NMS should be considered a medical emergency that is properly managed in an acute hospital.