We report the case of a 48-year-old man, admitted for atrial fibrillation with rapid heart rate and intense chest pain. A quick evaluation revealed a giant aortic aneurysm with severe aortic regurgitation and pericardial fluid without a trace of aortic dissection. Because of high suspicion of aortic rupture, an emergency surgery was planned, and a Bentall procedure was performed. On examination of the aortic wall revealing vertical wrinkling with a tree bark aspect, suspicion of syphilitic aortitis arose. The diagnosis was confirmed through postoperative serologic testing and histological examination. Histopathologic differential diagnosis, special treatment and follow-up are presented.