Advances in the treatment of stage 0 to III superior sulcus tumors mandate greater accuracy in establishing tissue diagnosis, assessing tumor extent, and staging. Currently, this is best accomplished by a combination of PA chest radiography, MRI, and needle biopsy. MRI is superior to other single imaging modalities for the overall assessment of local tumor extent, bone invasion, mediastinal invasion, and perhaps in the future, determining radiosensitivity. In patients with superior sulcus tumors, evaluation of the brain, liver, and skeleton for metastases may be advisable prior to treatment with preoperative radiation and radical surgical resection.