The purpose of this study was to assess the utility of MR imaging in identifying anatomic features of vascular rings. MR imaging of the thorax was performed in five consecutive children with symptoms and findings of vascular rings on barium esophagography. The diagnoses were subsequently proved at surgery and/or angiography. Preoperative definition of the anatomy was adequate and accurate in each case. Our preliminary experience with MR imaging in five patients with vascular rings suggests that this technique is an excellent alternative to angiography when further anatomic delineation of the abnormality is required.