We encountered two patients with small hypopharyngeal cancer who could be evaluated in detail by ultrasonography. Ultrasound images of a normal hypopharynx and those of the two patients are described. On ultrasonography, the larynx is visualized posteriorly to the thyroid cartilage nearly at the level of the carotid artery bifurcation by transverse scanning. Being separated by the adjacent epiglottic fold, the anterolateral wall of the pyriform sinus conty, and underwent ultrasonography to search for cervical lymph node metastasis. Both lesions were visualized as a hypoechoic mass occupying the cavity of the left pyriform sinus and, on color Doppler ultrasonography, showed rich color signals flowing from the epiglottic fold into the maining air is observed. Both patients were males in their 70s, were found to have a tumor 2 cm or smaller in diameter in the pyriform sinus by endoscopass. Hypopharyngeal cancer is often detected at an advanced stage because of inconspicuous pharyngeal symptoms. It occurs most frequently (60-70%) in the pyriform sinus. In the two patients presented here, the lesions were 2 cm or less in diameter and were located in the pyriform sinus, but they could be clearly delineated on ultrasonography. In ultrasonography of the neck, examination of the pyriform sinus may lead to the early detection of hypopharyngeal cancer in high-risk patients such as elderly males, heavy drinkers, and those with a smoking history.