Chest CT and magnetic resonance (MR) examinations of 28 patients with newly diagnosed or recurrent lymphoma involving the mediastinum were retrospectively evaluated for evidence of chest wall involvement. Computed tomography demonstrated seven sites of chest wall involvement in four patients; whereas MR demonstrated 14 sites in seven patients, including all sites shown by CT. Eight chest wall lesions were located in the extranodal soft tissues (three sites were contiguous with anterior mediastinal lymphadenopathy; three sites were contiguous with pleural/parenchymal disease; and one each involved the breast and multiple vertebral bodies). Six sites involved lymph nodes in the interpectoral (n = 4), submammary (n = 1), and infraspinatus (n = 1) areas. Lesion conspicuity in the chest wall was better on T2- than T1-weighted sequences and was best on short inversion time inversion recovery. Detection of chest wall lymphoma may alter staging; when present in this group of patients, it influenced management in two of the seven patients.