We present a case of malignant hyperthermia in which successful management included the intravenous use of dantrolene sodium. A subsequent operation under spinal anaesthesia with oral dantrolene prophylaxis did not lead to development of malignant hyperthermia. Since this syndrome is rare during regional anaesthesia, the role of prophylactic oral dantrolene in preventing the redevelopment of malignant hyperthermia in our patient is open to question.