Introduction:
Palpable or nonpalpable benign thyroid nodules are a common disease. In the symptomatic patients who complain from pain or obstructive sign, surgery is the therapeutic option that is associated with complications. Radiofrequency ablation is one of the new methods for treatment of benign thyroid nodule.
 Materials and Methods:
This randomized clinical trial, conducted on 88 patients who meet inclusion criteria. 8 patients were excluded during the study and the remaining 80 patients were randomly divided into two groups (In each group, 40). Initially, 40 patients (group A) with definite diagnosis of benign thyroid nodule are selected for RFA. The initial nodule size with ultrasound and baseline TSH should be recorded and then at intervals of 1 and 6 months later, size and TSH is evaluated. In the other group (B), prospectively 40 patients who were underwent thyroidectomy secondary to benign nodule, their complication such as hypocalcemia, hypothyroidism, obstructive sign and scar were evaluated. Finally, the data of these two groups of patients was compared.
 Results:
80 patients, including 20 males and 60 females with an average age of 48.3 ± 9.2 years, were evaluated. ANOVA analysis showed that the nodule volume decreased after RFA (P=0.002). Dysphagia improvement after thyroidectomy was statistically significant (P=0.003), in Group A dysphagia severity had not significantly decreased (P=0.337). Analysis showed improvement in foreign body sensation in both groups. The severity of dyspnea in both groups has declined. But group A’s patients was not statistically reduced (P=0.448 vs P=0.038). It was showed that cosmetic results in bothgroups were different, the mean beauty score improved in both groups but the satisfaction of beauty who underwent RFA were higher (P <0.001).Analysis showed that there were a statistically significant difference between both groups in hypocalcemia (P <0.035).Group B, 15 of 40 patients had hypocalcemia after surgery, but in group A, none of patients were being hypocalcemic. It was showed that the risk of hypothyroidism was different in both group, patients who underwent surgery are more likely to being hypothyroidism (P =0.048).
 Conclusion:
In comparison to surgery, RFA is a minimal invasive approach for treatment of benign nodule that is associated with less complication such as hypocalcemia, hypothyroidism and it has better cosmetic result. Improvement of obstructive sign in surgery approach is significant despite RFA approach. We suggested that patient who is asymptomatic and just suffer from abnormal neck appearance, radiofrequency ablation is better therapeutic option and who complain from obstructive sign, surgery is recommended.