Ultrasound studies of sixty five patients with thyroid mass histologically proven at KyungPook NationalUniversity Hospital from June 1983 to May were retrospectively analized. No specific sonographic characteristicsof thyroid mass lesions was found on the basis of histological diagnosis. Authors consider that ultrasound studymight be mere useful for detection and localization of a lesion, and guide to needle aspiration, monitoring thesize of a mass following therapy as well.