The presence of lymph nodes between the pectoralis major and minor muscles (Rotter's nodes) has been noted in the anatomic and surgical literature. We analyzed the appearance of the interpectoral space and nodes on chest CT scans of 25 patients without known chest wall abnormalities or causes for lymphadenopathy. In some of these cases small structures were detected in the interpectoral fat that could be either vessels or nodes. In addition we studied chest CT scans in six patients with interpectoral adenopathy due to metastases from breast cancer. The nodes were oval soft-tissue densities ranging from 1.5 X 1 cm to 3.5 X 3 cm in diameter.