We reported that most part of papillary carcinoma of the thyroid was able to be differentiated from benign nodules according to ultrasonographic findings including irregular shape, ill demarcation heterogeneous internal echo, and calcifications, and we proposed a classification into ten ultrasonographic patterns in the previous paper. But some patients were falsely diagnosed based on the classification. Therefore, we analyzed ultrasonographic findings of 289 patients with thyroid nodules in order to diagnose more accurately, especially those of falsely diagnosed patients were evaluated again in detail. Our conclusions were as follows; 1. The rate of diagnostic accuracy based on ultrasonography was 82.3%. 2. The irregularly shaped, ill demarcated nodules and/or those with heterogeneous internal echo generally indicated papillary carcinomas. 3. Calcifications were found in 47.6% of papillary carcinomas, 34.6% of follicular carcinomas, while 14.0% of benign nodules, significantly more frequent in former two groups. 4. Thirty-one of 50 (62.0%) patients with papillary carcinomas had the hypoechogenic internal echo, while had only 11 of 96 (11.5%) patients with benign nodules, significant difference was indicated. 5. Above-mentioned findings were not specific to papillary carcinomas. 6. Benign solitary nodules less than 3 cm in diameter were likely to be diagnosed as papillary carcinomas. On the other hand, papillary carcinomas over 3 cm in diameter were likely to be diagnosed as benign nodules. 7. Eighteen of 26 (69.2%) patients with follicular carcinomas were diagnosed as benign nodules based on ultrasonographic findings.