Objective:To Investigate the clinical efficiency and safety of ultrasound-guided sclerosing lauromacrogol injection therapy for thyroid cysts. Methods:Clinical data of 78 patients with thyroid cysts underwent ultrasound-guided aspiration and percutaneous lauromacrogol injections. All cysts were confirmed to be benign by fine-needle aspiration biopsy. Firstly, the complete aspiration of cystic contents was performed, and then lauromacrogol of approximately one third of the volume of thyroid cyst was injected into the cyst. We performed the therapy once a week, and the injection was repeated one to four times which depended on the reduction of the cysts. Results:1. One hundred and sixty-six times of injections were performed for 78 thyroid cysts. Volume of thyroid cysts decreased averagely by 71.6% ± 35.3% three months later, and there was a significant statistical difference before and after the therapy (P < 0.01). The completely cure rate was 52.6%(41/78)and the total effective rate was 84.6%(66/78); 2. The completely cure rates were different among diverse groups (P < 0.01). For the volume of cysts less than 5 mL, the completely cure rate was statistically lower than those above 5 mL, however, the statistical significance was not found in effective rate among different volume of thyroid cysts(P > 0.05);3. There was no obvious changes in thyroid function and titer of thyroid related antibodies after the therapy;4. The incidence of complications was low and no sever adverse effect was occured after therapy. Conclusion: Ultrasound-guided lauromacrogol injection is a feasible, effective and safe method, and can be chosen as the preferred therapy for thyroid cysts.