Background Percutaneous nephrolithotomy (PCNL) was mostly performed with fluoroscopy and/or ultrasonography.The safety and feasibility of PCNL performed totally under ultrasound are not clearly defined.Therefore,we introduce the 9-year experience of 8 025 ultrasound guided PCNL procedures from multiple centers in China performed by the same surgeon,to evaluate the feasibility and security of this technique.Methods From September 2004 to August 2013,8 025 cases,4 398 males (54.8％) and 3 627 females (45.2％),whose age ranged from 6 months to 85 years old,with upper urinary tract stones,underwent PCNL in our center and the supported hospitals.Puncture site selection and channel dilation were all guided using only Doppler ultrasound.Single stones were treated in 1 356 cases,there were 2 817 cases of multi stones,and 3 852 cases of stagh calculi.The pre-and post-operative imaging data,the intraoperative findings,operation time,perioperative complications,and related parameters were recorded.Results All procedures were successful.No patients died during the operation.Average operation time was 42 minutes (range 10 to 168 minutes),4 cases converted to open surgery,and 2 patients lost the diseased kidney due to refractory bleeding in the early stage of the PCNL.Ninety-four (1.2％) patients received blood transfusions and 20 (0.25％) patients needed highly selective renal artery embolization.Fifteen (0.19％) patients had a pleural injury.5 457 (68％) cases were completed by a single tract and 2 568 (32％) cases added more tracts.The mean stone size (longest diameter) was 2.8 cm (range 1.2 to 26.5 cm).The final stone-free rate was 85.5％.Residual stones occurred mainly in patients with renal dysfunction,medullary sponge kidney,and complete staghom calculi with a slim calyceal neck.Conclusions X-ray free Doppler ultrasound guided percutaneous nephrolithotomy is feasible and safe in a variety of cases of renal and/or upper ureteral stones.The probability of radiation hazard and adjacent organ injury is low.The morbidity from major complications was reduced remarkably after special training.It is worthy of wider use compared with fluoroscopy in patients with special kidneys (e.g.solitary kidney,spinal deformity,ectopic kidney) and in infants.