Magnetic resonance imaging (MRI) was performed in 7 patients with fibrosing mediastinitis. Comparison was made in each case to standard chest radiography and computed tomography (CT). Angiography was performed in 3 cases. Although MRI and CT were found to be equivalent in defining the extent of adenopathy, CT was superior at demonstrating calcifications, often important in making the diagnosis of fibrosing mediastinitis. MRI, however, offered complementary information, particularly in assessing vascular patency without the need for intravenous contrast media. On T2-weighted images, the adenopathy associated with fibrosing mediastinitis was noted to be of relatively low signal intensity, possibly indicating its benign nature.