The control of the neuromuscular blockade is part of the standard monitoring in general anaesthesia. However, the degree of blocking is affected by different disorders. We describe the neuromuscular monitoring in four patients suffering from central hemiplegia by stimulation of the ulnar nerve simultaneously on the paretic and the normal side. After application of non-depolarising muscle relaxants (Atracurium, Mivacurium, Rocuronium, Vecuronium) a resistance of the paretic extremity against the relaxant used was shown in all cases. A possible explanation for this observation is the spreading out of abnormal acetylcholine receptors over the surface of denervated muscle cells which could lead to a false estimation of the depth of the neuromuscular blockade. Therefore, in the clinical practice, neuromuscular monitoring must always be carried out on the normal extremity of the patient.