The purpose of this retrospective study was to estimate the frequency and severity of anaesthetic complications in patients with Duchenne's muscular dystrophy (DMD). Forty-four boys with DMD were exposed to anaesthesia and surgery 84 times during a period of 22 years (1965-86). The procedures took place at 15 different hospitals. Retrospective examination of the case records showed: 19 cases with local analgesia without any complications, and 18 of 65 general anaesthetics with minor or more serious complications. In ten cases an increase in body temperature above 37.5 degrees C was seen, five had abdominal pain and dark-coloured urine after surgery, and three had a critical perioperative course with a resemblance to malignant hyperthermia. The complications were almost exclusively related to the use of succinylcholine. The use of succinylcholine was dispersed through all ages. Three out of the eight patients with severe complications occurred 1.5, 2.5 and 4 years before the neuromuscular disease was diagnosed. Thus an unusual course of anaesthesia in male children calls for further investigation. Although it has been stated before that succinylcholine is contraindicated in patients with Duchenne's muscular dystrophy, the drug continues to be used.