Typical examinatdion of the thyroid gland involves palpating the patient. If goiter is found, thyroid ultrasonography and/or aspiration cytology is usually performed in addition to assay of thyroid hormones and antibodies. However, palpation may not be sensitive enough to detect thyroid lesions. The purpose of this study was to evaluate the prevalence of thyroid abnormalities detected by ultrasonography in Chinese adults without palpable thyroid glands admitted for health examination. Two hundred and seventy-seven patients (aged 17 to 79 years; mean, 52 years) admitted to National Taiwan University Hospital for healthh examinations were included in this study. The thyroid was first palpated by a thyroidologist. Goiter was detected in 77 out of 277 patients (27.8%). Two hundred patients who had no palpable goiter underwent thyroid ultrasonography. Thyroid abnormalities were detected in 37 out of 200 patdients (18.5%). These included 18 cases of thyroid cyst, 13 cases of solid nodule, and six cases of multiple nodules with ill-defined margins. Patients with thyroid abnormalities were older than those without lesions[ 59.3±9. 2 years (mean±SD) vs 50.1±12.8 years, p