Background The prognosis of ventricular tachycardia (VT) in children with overt heart disease is generally good, so the aim of this study was to review the prognosis and necessity of treatment of VT that detected by school-based heart disease screening. Methods and Results Of the 48 cases of pediatric VT that have been followed for 2-30 years, 17% were diagnosed at the first school-based screening test (12-lead ECG at rest) and the remainder who had premature ventricular contractions (PVC) on the resting 12-lead ECG required Holter ECG test and exercise stress ECG test to detect VT. In 90% of cases, VT in healthy children is idiopathic non-sustained VT and more than half of the present cases showed natural disappearance of the VT during follow up. In particular, cases of monomorphic PVC or maximum PVC runs less than 5 had a good prognosis. The cases of polymorphic VT and VT with heart disease continued for the long term. Conclusion Treatment is unnecessary for monomorphic VT with the maximum number of salvos less than 5. The necessity for treatment depends on the symptoms and profile of the VT. The prognosis for polymorphic VT and underlying heart disease is not good and may require implantable cardioverter defibrillator. (Circ J 2005; 69: 273 - 276)