The aim of this study was to compare the results of US-FNAB with definitive histological examination of thyroid nodular lesions. 590 patients who underwent surgery were reviewed (473 females, 117 males, ranging in age from 9 to 81 years, average 36 years). Histological evaluation of cytologically diagnosed benign nodules revealed nodular goiter in 407 cases (91.5%), Hashimoto's thyroiditis in 2 (0.4%), follicular adenoma in 31 (7%), papillary carcinoma in 2 (0.4%) and follicular carcinoma in 3 (0.7%). In the cytological group of follicular nodule (n = 71) histological diagnoses included: nodular goiter in 11 cases (15.5%), follicular adenoma in 36 (50.7%), papillary carcinoma in 2 (2.8%), follicular carcinoma in 20 (28.2%). The diagnosis of papillary carcinoma (n = 65) was confirmed histologically in 59 cases (90.8%), in the remaining 6 cases Hashimoto's thyroiditis and medullary carcinoma were diagnosed. In the cases diagnosed cytologically as medullary carcinoma (n = 8) histological diagnoses included: medullary carcinoma in 7 cases (87.5%). The cytological diagnosis of anaplastic carcinoma (n = 1) was confirmed histologically. These results support the value of US-FNAB in the diagnostics of thyroid neoplasms. US-FNAB performance was as follows: sensitivity 78%, specificity 97%, accuracy 92%, 2.3% of false positive and 6.1% of false negative results.