Evaluation of neoplasms of the salivary glands is a challenging surgical problem since there is no reliable laboratory procedure to confirm the diagnosis o€ a tumor or to indicate its nature or extent. Radionuclide scanning of the salivary glands can be performed using T~~~"'-pertechnetate, which is actively concentrated by the glands a t the level of the intralobar ducts. This test does not appear capable of detecting lesions which are not evident rlinically. The only two types of tumors which give a consistent scan appearance are Warthin's tumor, which appears 'hot' relative to the surrounding tissue, and metastatic lesions, which are 'cold' or distort the normal portions of the gland. I n general, primary malignancies also appear 'cold,' but the mixed tumor has a highly variable appearance. This procedure is useful in evaluating the topographic relationships of salivary gland neoplasms and in differentiating them from neck or facial masses, as well as in determining the functional impairment of the glands caused by the tumor. The results with salivary gland scanning t o date have been somewhat disappointing, although the application of recent technologic advances in this field and standardization of the scanning technique in a large series of patients may eventually justify the initial optimism in this diagnostic study.