Objective: To evaluate initial results of using flexible calico-pyeloscopy in control stone clearance during pyelolithotomy in treatment of multiple renal stones. Subject and method: 11 patients with multiple kidney stones underwent open pyelolithotomy combined with endoscopic control of stone clearance, using laser Homium energy to break stones at Thanh Nhan Hospital, Hanoi from March 2012 to October 2013. Patients with multiple stones in the kidney were only underwent open pyelolithotomy for stones removal. Then flexible tube station 6.5Fr was used to control the entire renal pelvis and find remained stones. Small stones were dragged out by Dormia basket, larger stones were fragmented by Holmium laser. Post-operatively, JJ stent was placed and withdrawn after 3 weeks. The preoperative characteristics of renal stones and results of stones removal by pyelolithotomy and remained stones control by flexible calicopyeloscopy were evaluated. Operative time and complications were recorded. Result: Flexible calico-pyeloscopy was performed in 10/11 cases (90.9 percent). General stone clearance rate for 10 cases performed by this technique was 90 percent (9/10). The technique was not done in one case due to renal bleeding. No patient had to undergo renal parenchyma incision for stone removal. No blood transfusion needed during the procedure. The average blood loss was 350ml (200-420ml). Conclusion: The flexible calicopyeloscopy during pyelolithotomy was feasible and effective in control calculi clearance in treatment of multiple kidney stones with minimal damage of renal parenchyma.