The incidence of thyroid nodules has been rising steadily during the last 30 years, since the introduction of new diagnostic methods such as ultrasonography and computerized tomography, thus posing a real challenge in determining the best approach strategy for treatment of this new 'epidemic'. We analyzed and compared data from several studies showing the prevalence of thyroid nodules on autopsy, palpation and ultrasonography to be 13%-60%, 0.5%-6.5% and 13.4%-46%, respectively. This demonstrates that thyroid ultrasonography is a very sensitive and accurate diagnostic tool the use of which, however, entails an increased number of incidentally discovered thyroid nodules without clinical significance. Therefore, ultrasonography of the thyroid should not be performed without clinical indication determined by thyroid specialist.