Since March 1993, high resolution ultrasonography has been performed in Pusan National University hospital as a routine preoperative check for patients with suspected or malignant thyroid nodules, identified by initial screening with fine-needle aspiration biopsy. Our one-year experience with 66 cases from June 1993 to June 1994 is as follows: 1) On the permanent sections, the nodule was a papillary thyroid carcinoma in 45.5%, a follicular adenoma in 27.3%, a adenomatous goiter in 22.7%, and a cyst in 4.5% of the total 66 cases, respectively. 2) Ultrasonographically, additional smaller nodule(s) was present in 60% of cases with a papillary thyroid carcinoma; also, papillary carcinomas were present in 61.1% of the permanent sections. In 2 cases of follicular adenomas, the additional nodules were papillary carcinomas on the permanent sections. 3) Multiple small calcifications within the nodule were found in 50.0% of the cases with a papillary thyroid carcinoma. 4) Enlargement of the jugular chain of nodes was found in 21.2% of the 66 cases, and was microscopically positive in 92.9% of the cases. Although not an essential element in initial screening, an ultrasonographic study of the thyroid may be quite useful in patients with suspected or malignant thyroid nodule.