Purpose: To assess the safety and efficacy of n-butyl cyanoacrylate (NBCA) and Iodized oil mixture as sclerotherapy for symptomatic simple renal cysts under ultrasound guidance. Materials and Methods: This prospective study conducted between June 2013 and October 2015, included 33 patients (22 males and 11 females) with 41 symptomatic simple renal cysts (> 5 cm). The mean age + SD was 54.5 + 11.4 (range 41 to 76) years. Before procedure, cyst volume was evaluated by US and non-contrast enhanced CT. Percutaneous real-time aspiration and injection of mixture of NBCA and iodized oil under ultrasound guidance was done. After the procedure, patients were followed up from 3 to 12 months with periodic US examinations. Primary endpoint is complete collapse or decrease in cyst diameter > 50% and elimination of symptoms. Failure was defined as decreased cyst volume < 50% and/or persistence of symptoms. Results: The mixture of NBCA and iodized oil was technically successful as sclerosing therapy for managing symptomatic simple renal cysts. During median follow up period of 6 months (range 3 to 12), complete disappearance was detected in 27/41 (65.9%), reduced diameter and dis-appearance of symptoms in 11/41 (26.8) and failed procedure (due to recurrence) was detected in 3/41 (7.3%). In all the cases with failure, the pre-procedure cyst diameter was ≥10 cm. After sclerotherapy, fever (