Marfan syndrome is an inherited autosomal dominant connective tissue disorder known for its multiple pathologies: musculoskeletal, pulmonary, ocular and cardiovascular. The criteria of Ghent facilitate its diagnosis. It requires a complete clinical examination as well as multiple imaging modalities. Early diagnosis and medical treatment with beta-blocker can delay the progression of aortic dilatation or possibly stop the pathological process of the aortic wall, as well as timely elective surgery are the key measures to improve the outcome of this disease. We report here the fortuitous discovery of a Marfan syndrome in a 19-year-old patient complicated with aortic dilatation.