Objective To investigate the clinical effectiveness and safety of ultrasound-guided percutaneous thermotherapy for benign thyroid nodules. Methods Ultrasound-guided percutaneous radiofrequency or microwave ablation was conducted following tru-cut biopsy of 50 benign thyroid nodules in 40 patients, including those with adenomas and hyperplastic nodules.The necrosis and shrinkage in the ablated areas were evaluated.The adverse effects and complications related to ablation were observed. Results All the 50 thyroid nodules were deprived of blood supply after ablation as shown by contrast-enhanced ultrasound, and the ablated area completely covered the size of the nodules.Follow-up ultrasound examination demonstrated that the ablated areas were shrunk to various degrees, including completely disappearance in 6 (12%), 32(64%) with the diameters reduced by more than a half, and 12 (24%) with the diameters reduced by less than a half.There were no skin burns in the neck, bronchial or esophageal injuries, recurrent laryngeal nerve palsy, or complication related to neck muscle injury. Conclusion Ultrasound-guided percutaneous thermal ablation is a safe, minimally invasive, controllable and definitely effective method for treating benign thyroid nodules.It has a great clinical potential.