Ultrasound has become established as the diagnostic procedure of choice in guidelines for the management of thyroid nodules by essentially every professional organization of endocrino- gists. In this, the second edition of their outstanding text on thyroid ultrasound, Baskin, Duick, and Levine have provided an invaluable guide to the application of gray-scale and color Doppler ultrasonography to state-of-the-art diagnostic eva- ation of thyroid nodules, and to the management of thyroid cysts, benign thyroid and parathyroid nodules, and thyroid cancer. Differences with, and additions to, the first edition highlight the extraordinary and dramatic advances in appli- tions of ultrasonography that have occurred in the past decade. The high yield of malignancy in ultrasound-guided fine-needle (FNA) aspirates of nondominant nodules in multinodular glands has altered our mistaken complacency in assuming that palpation-guided FNA only of palpable dominant nodules was adequate for diagnosis. Rather, ultrasound has taught us that the commonly held belief that malignancy is less likely in a multinodular gland is incorrect. Utility of ultrasound has gone far beyond just the initial diagnostic approach, as improved highly sensitive probes allow accurate characterization of the nature of thyroid nodules or lymph nodes, setting priorities for FNA and for serial monitoring for changes in size that could imply malignancy.