The adrenals are endocrine glands located cranially to the kidneys, deep in the abdomen, sheathed inside the opening of Gerota’s fascia. Since the introduction, in relatively recent times, of high-resolution probes and devices, it has been possible to perform ultrasound (US) studies of the adrenal glands. In 1980, Sample was the first to describe the ultrasound approaches best suited to studying the normal adrenal gland (Sample FW, Sarti DA. Renal, adrenal, retroperitoneal, and scrotal ultrasonography. In: Diagnostic ultrasound. Martinus Niyhoff, Hague, p 268–411, 1980). Although other imaging techniques (MRI, CT, scintigraphy) are considered primary techniques in the study of adrenal diseases, US can offer an important contribution both in pediatric patients and in adults, when disease induces an increase in the volume of these glands. The adrenals are studied together with the kidneys using convex 3.5 MHz probes or, preferably, multifrequency 5–2 MHz probes. Higher frequencies can be used to study the adrenal glands in children, in whom the glands are relatively larger and better defined. When available, tissue harmonics are routinely employed to reduce reverberation artifacts and obtain more detailed images.