Introduction: Thyroid nodules present serious problems, and mostly they do not carry neoplastic characteristics. Thus, they do not need to be surgically treated. Fine-needle aspiration biopsy (FNAB) is the most important diagnostic tool in the assessment of thyroid nodules and the prevention of unnecessary surgery. In this study, FNAB results of the patients operated for thyroid nodules were compared with postoperative histopathology results and the results of the frozen section were evaluated. Methods: In this study, 206 patients who underwent preoperative FNAB for solitary thyroid nodules and multinodular goiter in the 2 nd General Surgery Department of Istanbul Haydarpaşa Numune Training and Research Hospital between 1999 and 2003 years were included. Thyroid Disease Form and pathology reports were used to evaluate the patient files retrospectively. Results: The study population (n=206) consisted of 170 (82.52%) female and 36 (17.48%) male patients and the median age of the population was 46,56. When FNAB and histopathological examination results of the nodules were compared, four of 179 cases evaluated as benign lesions in FNAB were reported as thyroid cancer (2.23%) as a result of histopathological examination of the surgical specimen. Nine (69.24 %) of 13 cases as evaluated as atypical/suspicious, and all of the seven cases (100%) reported to be malignant in FNAB were reported as thyroid cancer after histopathological examination. The relationship between FNAB and histopathological results was statistically significant in all groups (p<0.0002). Discussion and Conclusion: It was concluded that FNAB is a useful method in the evaluation of thyroid nodules, and will prevent many unnecessary operations as a cheap and reliable diagnostic tool that can be used in the selection candidates for surgery and preoperative diagnosis of thyroid carcinomas. It was also evaluated that the frozen section may be useful in guiding the operation of patients in whom FNAB cytology is considered as atypical/suspicious.