The authors reported a case of false aneurysm in the lower third of the right brachial artery in a premature newborn (25 weeks of amenorrhea) subsequent to puncture performed 48 hours before. The treatment was surgical: resection of the false aneurysm and anastomosis (Monobrin 11-0 sutures) to restore the continuity of the brachial artery. After 6 months of follow-up, the course is favorable, with improvement in healing and absence of any functional disorder of the arm.