Aims: To evaluate the role of magnetic resonance imaging (MRI) in the assessme nt of children with suspected extrinsic tracheobronchial compression due to vasc ular anomalies. Methods: Retrospective case note review in a tertiary referral c entre. Twenty nine children who underwent dynamic laryngotracheobronchoscopy (DL TB) and were found to have a clinical suspicion of extrinsic tracheobronchial compress ion were evaluated. All subsequently underwent thoracic MRI within 10 days. The findings on endoscopy were compared to those of MRI, and where performed, echoca rdiography, cartography, and surgery. Results: There were 17 males and 12 female s (mean age 5 months, range 28 weeks gestation to 60 months). The most common pr esenting features were stridor and cyanotic episodes. MRI showed abnormalities i n 21 patients. There were five vascular rings (three double aortic arches and tw o right aortic arches) and 11 cases of innominate artery compression. Other vasc ular anomalies noted included aberrant right subclavian artery and aneurysmal le ft pulmonary artery. Echocardiography was generally found to be unhelpful in the diagnosis of extra-cardiac vascular abnormalities. Angiography was subsequentl y conducted in eight children; findings agreed with those shown on MRI. Surgery was performed on all five vascular rings, one innominate artery compression, and one aneurysmal left pulmonary artery. Surgical findings were also compatible wi th the preoperative MRI. Conclusions: This study shows the successful use of MRI as the initial imaging modality in endoscopically suspected extrinsic vascular compression of the upper airway. It enables accurate delineation of vascular ano malies and, unlike aortography, is non-invasive and does not require the use of contrast media. Aims: To evaluate the role of magnetic resonance imaging (MRI) in the assessme nt of children with suspected extrinsic tracheobronchial compression due to vasc ular anomalies. Twenty nine children who underwent dynamic laryngotracheobronchoscopy (DL TB) and were found to have a clinical suspicion of extrinsic tracheobronchial compression were evaluated. All subsequently underwent thoracic MRI within 10 days. The findings on endoscopy were compared to those of MRI, and where performed, echoca rdiography, cartography, and There were 17 males and 12 female s (mean age 5 months, range 28 weeks gestation to 60 months). The most common pr esenting features were stridor and cyanotic episodes. MRI showed abnormalities in 21 patients. There were five vascular rings (three double aortic arches and tw o right aortic arches) and 11 cases of innominate artery compression. Other vasc ular anomalies found incl uded aberrant right subclavian artery and aneurysmal le ft pulmonary artery. Echocardiography was generally found to be unhelpful in the diagnosis of extra-cardiac vascular abnormalities. all five vascular rings, one innominate artery compression, and one aneurysmal left pulmonary artery. Surgical findings were also compatible wi th the preoperative MRI. Conclusions: This study shows the successful use of MRI as the initial imaging modality in endoscopically suspected extrinsic vascular compression of the upper airway. It enables accurate delineation of vascular ano malies and, unlike aortography, is non-invasive and does not require the use of contrast media.