To determine the value of sagittal magnetic resonance (MR) in diagnosing thoracic abnormality, we reviewed the multisection sagittal spin-echo MR images of 13 normal subjects and 23 patients with a variety of thoracic abnormalities. In the abnormal subjects sagittal images were compared with transaxial MR performed with repetition time values of both 0.5 and 2.0 s. Sagittal images were most helpful in the evaluation of structures lying in the sagittal plane such as the thoracic aorta. Mediastinal masses in most locations were better seen and evaluated in the transaxial plane. However, the relationship of subcarinal masses to the trachea, left atrium, and pulmonary artery was better appreciated in the sagittal plane. The relationship of hilar masses to hilar vessels, bronchi, and the mediastinum was usually better seen on transaxial images. Also, the relationship of paramediastinal masses to the mediastinum was difficult to evaluate with sagittal scans.