OBJECTIVE To evaluate the efficacy of povidone-iodine sclerotherapy after percutaneous drainage of simple renal cysts in the treatment of symptomatic patients. METHODS Sixteen patients with symptomatic renal cysts were treated by percutaneous drainage and injection of povidone-iodine solution. The cysts were drained by a nephrostomy tube catheter, and povidone- iodine injections were repeated every 24 hours for 3 days. All patients were followed up by ultrasound examination during a period ranging from 1 to 4 years (mean 1.8 years). RESULTS Thirteen patients experienced recurrence of cysts, while complete resolution was observed in only three patients. Of the cysts that recurred, only partial resolution in cyst diameter was observed (from 3-10.5 cm to 2.4-8.6 cm). During the follow-up period, 12 of the 16 patients (75%) continued to have pain that necessitated additional treatments. CONCLUSIONS Povidone-iodine sclerotherapy is followed by a high rate of recurrence and is therefore not indicated for the treatment of symptomatic simple renal cysts.