Anesthesia for patients with Steinert's syndrome (myotonic dystrophy, MD) is a challenge for the anaesthetist. MD is a multisystemic disease and the neuromuscular symptoms can be associated with sleep apnea, endocrine disorders (diabetes, hypogonadism, hypothyroidism), cardiac, gastroenteric or cognitive disorders (mental deficiency, attention disorders). The diagnosis is facilitated when one or more of these symptoms are associated with the neuromuscular symptoms; however, the latter are not always present at the onset, which makes the diagnosis of MD a difficult and often late one. The choice of drugs and the choice of anesthesia in these patients can be very challenging for many reasons. A myotonic crisis can be triggered by several factors including hypothermia, shivering and mechanical or electrical stimulation. These patients are very sensitive to the usual anesthetics such as hypnotics and paralyzing agents (both depolarizing and nondepolarizing). The following case report describes pathophysiological considerations and a technique for anaesthesia during thoracic surgery that has been able to assure hemodynamic peroperative stability, early extubation and prolonged respiratory autonomy in a patient affected by this genetic disorder.