Background To make diagnosis of Marfan syndrome (MFS), Ghent nosology is the ���gold standard���. In the Ghent nosology, clinical features are assessed within seven body 'systems' (skeletal, ocular, cardiovascular and pulmonary system, skin and integument, dura, and family/genetic history) to determine whether that system provides a major criterion (M), or only system involvement (I). A diagnosis of Marfan syndrome requires a major criterion in two systems and involvement of a third. In this study, we have evaluated usefulness of MDCT for diagnosis of Marfan syndrome by Ghent nosology. Methods and Results Forty seven patients (M:F=23:24, mean age: 33.8 years ; range 12-57) with MFS, who had undergone MDCT angiography of the aorta, were included in this study. MDCT could give positive signs of criteria in 4 systems involving skeletal, cardiovascular, pulmonary and dura. In skeletal system, pectus deformity (28%), scoliosis (21%) or spondylolisthesis (4%), protrusion acetabulae (24%) could be diagnosed by MDCT. Dilatation of the aortic root (79%), dissection of the ascending aorta (3%), dilatation of the pulmonary artery (47%), calcified mitral annulus (0%), and other dilatation or dissection of the aorta (55%) were visualized by MDCT. Apical blebs in pulmonary system (35%) were noted in the lung window setting of MDCT. Finally, presence of sacral dural ectasia (66%) could be evaluated. MDCT could identify 1(I) in 3 patients, 1(M) in 8 patients, 1(M)1(I) in 8 patients, 2(M) in 15 patients, 2(M)1(I) in 11 patients, and 2(M)2(I) in 1 patient. Therefore, MDCT alone was sufficient for diagnosis in 12 (26%) of 47 patients. Combination of MDCT findings and a genetic analysis of fibrillin-1 (FBN1) mutation made diagnosis of MFS in 26 (55%) of 47 patients. Conclusions Our study shows that MDCT plays an integral role in assessment of Ghent nosology to facilitate diagnosis of MFS. Knowledge and awareness of MDCT findings of Ghent nosology permit a comprehensive diagnosis of MFS that allows better patient care.