Long QT syndrome (LQTS) is caused by a change in cardiac repolarization due to functional ion channel dysfunction which is associated with an elongation of the QT interval (hence the name) in the electrocardiogram and a predisposition to cardiac rhythm disorders (e.g. torsade de pointes, TdP) as well as cardiac events up to sudden cardiac death. There is a congenital (cLQTS) and an acquired (aLQTS) form of the disease. The prevalence of cLQTS is 1 in 2000 but aLQTS is much more common and includes a grey area due to many asymptomatic patients. The LQTS is, therefore, more common than malignant hyperthermia which is much discussed in anesthesiology and has a reported prevalence in the population of 1:3000. Considering the prevalence of both aLQTS as well as cLQTS the importance of the LQTS seems to be underestimated in current perioperative care. Potential perioperative risks of such patients can be significantly reduced by appropriate patient management. This includes adequate preoperative preparation, the correct choice of anesthetic medication as well as adequate perioperative monitoring and preparedness for immediate pharmaceutical and electrical intervention in case of typical cardiac rhythm disturbances, such as TdP arrhythmia.