Short QT sydrome (SQT) is one of the rarely seen arythmia causes related to sudden cardiac death. An important part of the patients are diagnosed during the examination due to cardiac arrest. Therefore, diagnosing asymptomatic patients is lifesaving. In this case report, we presented a five-year old asymptomatic female patient how to put the SQT diagnosis. There was no complaint of the patient who had been directed to pediatric cardiology polyclinic due to murmur. In her electrocardiography (EKG), QTc duration was determined in lower limits. However, when the patient's family history was examined in a detailed way, suspicious deaths were recognized. In the patient's 24-hour holter EKG; SQT was diagnosed by establishing average QTc duration as 340 ms together with sharp, narrow T waves. Satolol treatment was initiated to the patient. To diagnose asymptomatic SQT patients, a decent family history must be obtained. Spot EKG is insufficient to rule out the diagnosis. All patients with suspicious death histories in their familieis must be directed to pediatric cardiologists.