OBJECTIVE This study aimed to evaluate the efficacy of flecainide therapy in neonates and infants with drug resistant incessant supraventricular tachycardia. METHODS The study included 11 neonates and infants who received medical and/or ablation therapy between January 2010 and December 2013. Mean patient age and weight were 101.6 ± 96 days and 5.3 ± 1.9 kg respectively. Of the 12 patients, 5 underwent ablation between January 2010 and December 2011, and 6 were treated medically between January 2012 and December 2013. Mean follow-up time was 18 months (6 months-4 years). RESULTS The antiarrhythmic agent flecainide only became available in Turkey in 2012, and the most noteworthy point was its addition to the therapy administered prior to ablation (adenosine, esmolol-propranolol, propafenone, amiodarone and cardioversion). In all 6 patients admitted between January 2012 and December 2013, refractory SVT was successfully treated with the administration of a triple therapy regimen of esmolol-propranolol, amiodarone and flecainide. One patient with myocarditis developed an atrial flutter complicated by a concealed accessory pathway and was put on extracorporeal membrane oxygenation (ECMO) support due to cardiopulmonary failure. The SVT was terminated, but the patient died on the fifteenth day of ECMO support. One patient with recurrent tachycardia, who had previously undergone ablation for a complex cardiac anomaly and Wolf-Parkinson-White syndrome, was treated with ablation again. No recurrence of tachycardia was observed in any of the other 9 patients. CONCLUSIONS It appears that the use of propranolol-esmolol and amiodarone combined with flecainide in the medical treatment of drug-resistant SVT may reduce the need for ablation in critical neonates and infants.