The technique of circulatory arrest under deep hypothermia has completely changed the therapeutic outlook of some congenital heart malformations in the newborn. The authors have tried this method particularly in neonate cases of the interventricular communication. This experience bears on ten newborn cases aged 3 to 11 months. Surgical indication was mandatory because of global heart failure, unresponsive to conservative treatment. Intracardiac correction is realized under optimal conditions of operative technique by means of the circulatory arrest. In six cases, the interventricular communication is large and isolated; in four cases there were multiple interventricular communications. The immediate postoperative is favourable in all cases. One was reoperated for a residual shunt. Evolution is satisfactory in nine cases. There was one late death. Hemodynamic controls prove the soundness of this method of treatment. Favourable results up to 2 1/2 years after the procedure encouraged the authors to extend the indications for deep hypothermia and circulatory arrest to other congenital anomalies of the newborn.