A retrospective analysis of results of magnetic resonance imaging (MRI) was conducted in 28 patients with uni- or bilateral pulmonary hilum lesions and findings compared with those of computed tomography (CT). All abnormal hilar masses examined were between 1 and 5 cm in diameter and were easily detected by transverse axial imaging. Contrast of their images was very high in relation to hilar bronchovascular elements in the two types of spin echo sequence with a short TR (0.5-0.7 s) and a long TR (1.5-2 s). Differentiation between tumoral or adenopathies and vessels was simpler than with CT with intravenous contrast. For screening of possible extension of hilar tumors. MRI appears to be superior to CT for providing data on vascular relations of lesions but inferior to CT for determining bronchial relations. Mediastinal extension of hilar tumors is easily defined by the short TR sequence but MRI supplies data of greater value than CT only in a low proportion of cases and then partly as a result of complementary coronal and sagittal imaging.