Background: Percutaneous renal cyst sclerotherapy (PRCS) as a treatment for renal cysts is usually performed with a high concentration of ethanol (≥ 90%). This study reviewed cases in which a lower concentration of ethanol (83%) was used for the procedure in dogs. Methods: Records of cases of renal cysts treated by sclerotherapy using 83% ethanol in dogs were reviewed. Outcomes of the treatment were evaluated by comparing volumes of renal cysts before the procedure and the volumes after treatment, using ultrasound images with the volume reduction rates classified as follows: < 50% of initial volume (failed); ≥ 50% but < 80% of initial volume (partial success); ≥ 80% but < 95% of initial volume (great success); ≥ 95% of initial volume (complete success). Results: Out of nine dog kidneys, renal cysts sclerotherapy with 83% ethanol achieved partial success in one kidney, great success in four, and complete success in the other four. No side effect was observed. The mean of the volume-reduction rates was 90.00 ± 11.00 while the minimum and maximum reduction rates were 65% and 100%, respectively. Conclusions The lower ethanol concentration (83%) is good for disinfecting kidneys in PRCS.