Nuclear medicine techniques have a long history in pulmonary medicine, one that has been continually changing and growing. Even longstanding methods, such as perfusion scanning for embolic disease or for pretherapy pulmonary function evaluation, have largely withstood the test of recent careful scrutiny. Not only have these techniques remained an important part of the diagnostic armamentarium, but we have learned how to use them more effectively. Furthermore, because of technical advances, we are in a phase of expanding roles for nuclear imaging. Gallium citrate scanning for the mediastinal staging and follow-up of lymphoma has been recognized as a valuable adjunct to the anatomic information provided by CT and MRI. With the growth of PET technology in areas that have been explored in a limited fashion until now, such as noncardiogenic pulmonary edema and lung carcinoma, evaluation and management of these patients may substantially improve. Finally, in the field of radiolabeled monoclonal antibodies, attention is now being turned to both the diagnostic and the therapeutic problems presented by lung carcinoma. As radiolabeling methods are refined and as new and better antibodies are developed, radioimmunodetection and therapy in lung carcinoma may begin to make inroads on this common and hard to control disease.