Compared with microwave ablation (MWA), percutaneous radiofrequency ablation (RFA) and laser ablation (LA) have been recommended as minimally invasive treatments for patients with symptomatic benign thyroid nodules (BTNs) because of the large number of clinical applications. This prospective multicenter study sought to evaluate the clinical outcomes of RFA and MWA for BTNs. In eight participating institutions, the total number of 1252 patients treated by RFA and MWA were 649 ones with 687 BTNs and 603 ones with 664 BTNs, respectively. The clinical outcomes including the nodular maximal diameter reduction ratio (MDRR), the nodular volume reduction ratio (VRR), and the incidence of complications were compared to evaluate the efficacy and safety of the two techniques. The results for the nodular MDRR and VRR in the RFA group were significantly better than those in the MWA group at 6 months and later follow-up, and the major complication rates of 4.78% and 6.63% in RFA and MWA groups showed no statistically significant differences. In conclusion, both RFA and MWA are safe and effective techniques for selected patients with symptomatic BTNs. The achieved MDRR and VRR in the RFA group were greater than those in the MWA group at 6 months and later follow-up.The thyroid nodule is one of the most common lesions in clinical practice 1 and has been increasingly detected in approximately 50% of the general population by ultrasound (US) examination 2 in the past two decades due to the widespread use of radiological imaging. Benign thyroid nodules (BTNs) proven cytologically by fine-needle aspiration biopsy (FNAB) account for 85 to 95% of all thyroid nodules 3 . It is unnecessary to treat most BTNs because of their lack of symptoms and slow growth 4 . Therapy is mainly focused on patients with progressive nodular growth or cosmetic problems and symptoms, which are related to nodular volume 5 . Therefore, it is essential for the treatment of BTNs to maximize the nodular volume reduction ratio (VRR) and minimize complications because of the anatomical features of the thyroid and its adjacent important structures.After over a decade of clinical application, percutaneous radiofrequency ablation (RFA) and laser ablation (LA) under US guidance have become minimally invasive treatments for patients with BTNs, especially for nonsurgical candidates, surgical high-risk individuals or those refusing surgery 5,6 . Low complication rates and high nodular VRRs for RFA and LA have been confirmed in the treatment of BTNs [7][8][9] , and the preservation of thyroid