Abstract: Objective：To evaluate the efficacy and safety of percutaneous nephrolithotomy (PNL) in oblique supine position for the treatment of upper urinary tract stones. Methods：A total of 94 patients with upper urinary tract stones were treated with PNL from January 2014 to December 2015 in Changshu No.2 People’s Hospital. Their clinical data were analyzed retrospectively and patients’ postoperative residual stone, bleeding and infection were recorded. Results：PNL was completed successfully in all 94 cases. Stones were cleared in 90 cases at the first stage and 4 cases at the second stage. Five patients required blood transfusion, and one of them underwent renal artery digital subtraction angiography (DSA) embolization to stop bleeding after the conservative treatment was ineffective. Eight cases of urinary sepsis were cured by antiinfection therapy, and no septic shock occurred. From 2 to 24 months followup, all patients were alive, and no patients needed further surgery because of stone recurrence. Conclusions：The rate of one stage stone clearance of PNL in the oblique supine position is high, and the complications are controllable, so it is safe and effective in treating upper urinary tract stones.