Objective: Evaluation of result of the puncture technique into the renal calyces based on principle of right triangle in PCNL with fix C-arm and no the contrast.Materials and Methods: 102 cases of percutaneous nephrolithotomies have been performed at Department of Urology of Hue Central Hospital from Jan 2015 to Apr 2017 with no the contrast.Results: Mean age of patients was 47.2 ± 10.7 years (23 -69). Renal pelvis stones in 14 cases (13.73%), renal calyx stones in 15 cases (14.70%), staghorn stones in 29 cases (28.43%) and renal pelvis-calyx stones in 44 cases (43.14%). Hydronephrosis of grade I: 33 cases (32.35%), grade II: 36 cases (35.30%), grade III: 9 cases (8.82%), no hydronephosis: 24 cases (23.53%). Percutaneous renal access into inferior posterior of the kidney in 47 cases (46.08%), middle calyx 42 cases (41.17%) and superior calyx 13 cases (12.75%). Average time of puncture: 8 ± 18 seconds (fastest 3 seconds and slowest 67 seconds). Successful punture into calyx was 100%. No accidents in the technique. Conclusions:The puncture technique into the renal calyces based on principle of right triangle in PCNL is a good, fast, exact and safe technique.