Objective To study the clinical value of ultrasound guided percutaneous anhydrous ethanol sclerotherapy in treatment of benign cystic lesions of thyroid. Methods Ninety-five cases of thyroid benign cystic lesions were seleted, including 26 cases of simple cystic lesions , 69 cases of complex cystic lesions. All the patients were treated by ultrasound-guided percutaneous aspiration of cyst fluid and injection of anhydrous ethanol sclerotherapy , and its clinical efficacy during the following up 12 months was evaluated. Results In 95 patients after 3 months the total cure rate was 36.84%, the total effective rate was 88.42%; after 3 months of operation, simple cystic lesion cure rate was higher than that of complex cystic lesions, there was significant difference between the two types of cystic lesions(P＜0.05), there was no significant difference in the effective rate of treatment. No obvious complication was observed after therapy. Conclusions Ultrasound guided percutaneous ethanol sclerotherapy in treatment of thyroid benign cystic lesions has the benefits of obvious curative effect, simple operation,and mild trauma;it is a safe and reliable treatment.