Mycotic aortic aneurysms are exceedingly uncommon in infants and they have a high risk of rupture. Their surgical management is extremely challenging. We report a case of a 22-month-old girl who presented with abdominal pain and fever revealing a ruptured mycotic aneurysm of the infrarenal aorta. The surgical treatment consisted of a ligature of the proximal and distal ends of the aneurysm. Postoperative course was significant for hypertension. A year and a half follow-up showed no other complications. Limited data are available concerning our chosen technique, but the reported cases showed a good short-term outcome.