Introduction. Percutaneous aspiration sclerotherapy is indicated for the treatment of symptomatic renal cysts. The efficacy of various sclerosing agents have been sources of ongoing debate and disagreement. Purpose of the study. The aim of this study was to evaluate the efficacy and safety of the use of aethoxysklerol 3% in the minimally invasive treatment of simple renal cysts. Material and methods. Between 2018 and 2021, the results of 43 symptomatic patients with an average age of 55 years, of which 22 men and 21 women, with renal cysts larger than 5 cm, detected on ultrasonography or CT Bosniak I. Under local anaesthesia, through a percutaneous ultrasound guided approach with an 18G needle, puncture the collection with aspiration of the liquid, then inject 1.0 ml of aetoxysklerol 3% solution for every 100 ml of aspirated liquid. Results. The complete disappearance of the renal cyst varied between 80% - 96% after a follow-up period of 3-36 months, for cysts up to 7.0 cm. The partial reduction of the renal cyst >50% varied between 35% - 55%. Minor complications 2 cases 4.6%: low fever and microhematuria. The success rate of sclerotherapy was inversely proportional to cyst size (p=0.01). Conclusions. Sclerotherapy with aetoxysklerol 3% is a more reliable, cost-effective minimally invasive method for the treatment of simple renal cysts.