The thyroid gland provides ideal anatomic conditions for sonographic investigations. Apart from the scintigraphy the sonography of the thyroid gland, therefore, stands in the first place as imaging procedure. After a short description of the investigation method and its ability of statement typical sonographic findings are demonstrated. The differentiation into diffuse or nodous strumata, the proof of typical focal findings such as autonomous adenomas or tumours or an increased vascularization in the region of the thyroid gland present an essential enlargement of the spectre of the modern diagnostics of the thyroid gland.