Because of its high sensitivity and noninvasiveness, thyroid and parathyroid ultrasonography is the first-choice examination modality in cases of thyroid and parathyroid disease. In these cases, qualitative verification can be based on the results of B-mode examination, while color Doppler method information can serve as the basis for functional evaluation. Differentiating follicular carcinoma from follicular adenoma, mild Basedow′s disease from painless thyroiditis remains difficult, however, even with the full use of ultrasound. Although ultrasonography can show pathologic enlargement on a visible parathyroid gland, widespread exploration is necessary, given the frequency of embryologic dislocation. Percutaneous ethanol injection therapy is appropriate in some less invasive cases of thyroid and parathyroid disease. Thyroid and parathyroid ultrasonography appear likely to become the modality of choice in the clinic.