The clinical records of 1,071 cases of extrathoracic malignant neoplasms seen over a 2 year period sere reviewed: 163 had abnormal chest films, and 25 of these showed evidence of mediastinal and/or hilar lymph node metastases. The primary malignancies which metastasized to intrathoracic lymph nodes included eight tumors of the head and neck, 12 genitourinary malignancies, three carcinomas of the breast, and two malignant melanomas. The chest films were analyzed to determine the distribution of lymph node groups involved. Unilateral lymph node enlargement occurred in eight. The most frequently detected lymph node group was the right paratracheal chain (60%), while the subcarinal and posterior mediastinal groups were rarely affected. Of the 25 cases, 10 had radiographic evidence of hematogenous or lymphangitic metastases in addition in the lungs. Metastatic disease from extrathoracic neoplasms should always be considered in the differential diagnosis of hilar and mediastinal adenopathy.