Children with the long QT syndrome (LQTS) are prone to life threatening ventricular arrhythmias. These arrhythmias may result in syncope and seizures that are often attributed incorrectly to a seizure disorder or to common fainting. The untreated mortality for symptomatic children with the LQTS is high but is improved significantly with therapy. Paediatricians should be aware of the presentations of the syndrome. Recommendations for screening for the syndrome are given.