Six cases of ventricular tachycardia seen at Children's Hospital since 1970 are presented. Diagnosis was made by classical electrocardiographic criteria and/or pacing studies. Three patients, aged 3/12-4 years, had paroxysmal ventricular tachycardia with signs and symptoms of heart failure. Two patients had probable associated myocarditis. Ventricular rates were 220-280/min. One case responded to quinidine, one converted to sinus rhythm during pacing studies. A third patient, age 16 months, was unresponsive to digoxin, procainamide, propranolol and d/c cardioversions. Aprindine HCL administered IV, with cardioversion, converted the patient to sinus rhythm. Three cases of nonparoxysmal ventricular tachycardia presented with rates of less than 130/min. Two were asymptomatic, one had dizziness. Ventricular tachycardia was suppressed by exercise in all. We recommend no treatment for nonparoxysmal ventricular tachycardia in absence of symptoms. One patient with paroxysmal ventricular tachycardia is in sinus rhythm on no drugs, one is on propranolol and the third is maintained on Aprindine. Aprindine HCL is useful in treatment of life threatening ventricular arrhythmias.