We studied 81 consecutive cases of papillary carcinoma in surgically removed thyroid glands to elucidate the correlation between their ultrasonographic and pathohistologic characteristics. The tumor parenchyma in 71.6% of these cases contained hyperechoic structures, most of which were minute spots, some with and some without attenuation, that corresponded well with the psammoma bodies observed on histologic examination. The larger spots were assumed to be coarse calcification in necrotic tissue. Dense hyalinized fibrosis in tumor parenchyma also produced intense reflection that caused hyperluminous spots. These hyperechoic structures show a higher incidence of lymphnode or intraglandular metastasis. Most papillary carcinomas of the thyroid were hypoechoic. In the pure follicular variant of this type of cancer, the foci and the associated predominant follicular structures were more echoic than were purely papillary carcinomas. Thus ultrasonographic methods were not always able to diagnose papillary carcinoma of the thyroid.