[en] Plexiform neurofibroma usually occur in the neck, pelvis and extremities, but they may seen virtually at any location, including the thorax. To evaluate the findings and the role of CT in plexiform neurofibromatosis of the mediastinum. We retrospectively reviewed the clinical results and thoracic CT scans of five patients with pathologically proved plexiform neurofibromatosis of the mediastinum. The CT scans were reviewed with attention to the distribution of the lesions, appearance and attenuation of mediastinal lesions, enhancement pattern after intravenous contrast infusion and associated findings such as intercostal neurofibroma. In all five patients CT scans demonstrated fusiform low attenuated masses which were oriented longitudinally and extended over multiple contiguous scans along the distribution of major mediastinal nerves. In four patients, mediastinal lesions appeared infiltrative, obliterating adjacent mediastinal fat plane. One patient had well defined fusiform masses along the major mediastinal nerves. Postcontrast enhanced CT scans revealed slight central enhancement in two patient and no contrast enhancement in three patients. Associated findings such as neurofibromas of intercostal nerves and sympathetic trunk, or subcutaneous neurofibromas were detected on CT scans in all five patients. Characteristic CT findings of low attenuation masses along the major mediastinal nerves are helpful to differentiate plexiform neurofibromatosis from mediastinal lymphadenopathy and to prevent from misreading as a malignant disease