BACKGROUND: Contrast-enhanced CMR angiography (CE-CMRA) is being increasingly used for diagnosing aortic arch anomalies, planning interventions and follow-up assessment. We sought to establish normal values for the diameters of the thoracic aorta and reference curves related to body growth in children using CE-CMRA. RESULTS: CE-CMRA was performed in 53 children without cardiovascular disease. The median age was 9 years (range 2 - 20 years), weight 30 kg (range 12 - 75 kg), height 131 cm (range 81 - 184 cm), body surface area (BSA) 1.05 m2 (range 0.52-1.9 m2). Aortic diameters were measured at nine standardized sites on oblique maximum-intensity projection (MIP) images. Regression analysis of diameters in relation to BSA demonstrated linear relationship between the cross-sectional aortic diameters and the square root of BSA (BSA0.5). Normative diameters were (0.57 + 19.37*BSA0.5) mm for the aortic sinus, (-3.52 + 18.66*BSA0.5) mm for the first segment of the aortic arch, (-3.37 + 16.52*BSA0.5) mm for the isthmic region and (-1.27 + 9.89*BSA0.5) mm for the descending aorta at the level of the diaphragm. Normative curves are presented. CONCLUSION: This study provides normative values for aortic diameters in children measured by CE-CMRA. These data may serve for making the diagnosis of pediatric arch anomalies, assessing the need for treatment and planning interventions.