Malignant hyperthermia has been reported by many authors since Denborough [1960] first described concerning anesthetic death in a family. Malignant hyperthermia is characterized by a hypermetabolic state [tachycardia, tachypnea, hypercarbia, hypoxia, cyanosis, hypotension, high fever and muscle rigidity] and is related to a hereditary defect of skeletal muscle. In susceptible individuals, it is triggered by potent inhalational anesthetics, depolarizing muscle relaxant [Succinylcholine], amide type local anesthetics [prototype lidocaine] and occasionally by stress due to emotional and environmental factors. Unrecognized and untreated malignant hyperthermia is associated with a very high mortality rate. Recently authors have experienced malignant hyperthermia in 5 year old male child who was diagnosed to have patent ductus arteriosus and interatrial septal defect associated with congenital physical deformities such as short stature, hypotrophic muscles and genu valgus deformity of lower extremity, indirect inguinal hernia and Ramphant caries. [KTCS 1982;2:230-237]