A prolonged electrocardiographic QTc interval may be unsafe during general anesthesia; thus successful anesthetic management in patients affected by congenital long QT syndrome include avoidance of any event that increases sympathetic activity and drugs that prolong QT interval. Propofol seems to have less effect on the QTc interval than tiopentone in normal subjects. This report suggest that propofol administration and infusion in clinical doses in a patient with Jerwell Lange-Nielsen syndrome may be safe and without increase of duration of QTc interval. The most marked changes in HR and QTc followed tracheal intubation and awakening suggesting a specific effect of cathecolamines.