A prospective study by nuclear magnetic resonance in 7 infants with respiratory disorders and with a barium swallow suggestive of anomalies of the aortic arch was conducted. It allowed the definition of an investigation protocol including sedation, RF coil adapted to infants size, naso-gastric tube placement, thin MR sections. Sequences are T1 weighted with ECG gating in two perpendicular frontal oblique and transverse oblique planes determined on a scout sagittal MR acquisition. Precise determination of the anatomy of the vascular malformation and its relationship with the trachea and esophagus were obtained. After definition of the investigation protocol, MRI was found to be a very effective evaluation technique for aortic arch anomalies. It can be proposed as an alternative to preoperative digital angiography. Its indications remain to be defined in relation to the clinical features and the results of the chest X-ray and barium swallow.