From April 1988 through April 1989, 1,999 subjects (826 males, 1,173 females) underwent ultrasonic examination of their abdominal organs and thyroid gland. 269 subjects (13.5%) showed abnormalities in their thyroid gland. 10 cases of thyroid cancer were detected, with a detection rate of 0.12% in males and 0.77% in females. The histological type of nine of the thyroid cancers was papillary carcinoma, and the other one was follicular carcinoma. The thyroid cancers were under 2.0 cm in all patients, and 3 patients had microcarcinoma. Screening of thyroid diseases is useful for patients undergoing abdominal ultrasonic examination.