History and Objectives: Due to the prevalence of thyroid nodules and discrepancies on the specificities of the patients, type of thyroid nodule, outcome and side effects of treatment and in order to determine the thyroidectomy indications, the present study was designed and carried out on 220 patients referred to the Ayatollah Taleghani hospital in 1992-1996.

Materials and Methods: The study was carried out on the existing data. Personal data age, sex, clinical symptoms, isotopic scan results, presurgical diagnosis and pathological findings after surgery were taken from patient’s records and a descriptive statistical analysis was done.

Results: From 3810 surgical operations, 220 cases (5.8%) (76.8% female and 23.2% male) was due to thyroidectomy procedures. Mean age of patients was 35±12 years and 71% of the patients were under 40 years of age. Cold nodules (65.9%), warm nodules (23.6%), hot nodules (8.7%) and without nodules (1.8%) were the most prevalent type of thyroid nodules. 36 cases (16.4%) of the cases were malignant and 83.6% of the cases were benign. The most prevalent type malignancy was papillary carcinoma (64%) and 25% of the cold nodules were malignant. No malignancy was observed in warm and hot nodules.

Conclusion: In some of the cases FNA was not performed. The data indicated the 16.4% of the cases has malignancy. It is suggested that all patients with thyroid nodules and definitive and uncertain FNA, the cancerous tissue should be removed by surgical procedure. Reduction of cold nodules by L-thyroxin does not eliminate the possibility of malignancy. However, in malignant cases, rapid accumulation of fluid after drainage and observation of papillary carcinoma of cyst even with negative cytological findings, probability of cancer and surgery should be considered. Euthyroid patients with hot nodules should be kept under supervision and in the case of hyperactivity of small nodules radioactive iodine may be prescribed. However, for nodules with diameter of 5-6 cm surgery is recommended.