Abstract: Objective:To investigate the methods and complications of ultrasound-guided percutaneous nephrostomy (PCN) for treat -ing cancer-related hydronephrosis. Methods:From June 2003to December 2015, 289 patients ( 342 kidneys) with cancer-related hy -dronephrosis were treated by ultrasound- guided PCN in Fujian Provincial Hospital. Among the 97cases of renal insufficiency, 4 pa-tients were treated with hemodialysis before PCN. Except for the anterior mid calyx of nine kidneys in nine patients, the posterior mid or lower pole calyx of all other kidneys was punctured with ultrasound guidance. With the one-step PCN technique,8F pigtail nephros -tomy tubes were placed into six kidneys in six patients; with the Seldinger PCN technique, 14F balloon and Malecot catheters were placed into 25kidneys in25patients and311 kidneys in258 patients, respectively. Results:No severe bleeding and injury in the intes-tine, liver, spleen, pleura, or lung occurred. Two pigtail tubes were blocked one week after PCN. Seven balloon catheters failed to drain well because of the tip and balloon of the catheters located in the proximal part of the dilated ureters. Four balloons slipped out of the collection system of the kidney because of the auto- deflation of three balloons and one case of meager renal parenchyma failing to hold the balloon after a severe hydronephrosis was emptied. All, except1, Malecot catheter drained well, and 8/9 PCNs through anteri-or mid calyx were successful. Serum creatinine levels were significantly decreased in all the 97patients with renal insufficiency, of which81cases returned to normal, and no one needed persistent hemodialysis. Conclusion: Ultrasound-guided PCN is safe and effec-tive for treating cancer-related hydronephrosis. For appropriately selected patients, puncturing the anterior mid calyx may be an op -tion without additional complications. One- step pigtail nephrostomy tubes are recommended for patients with poor systemic condi -tions. For patients with long life expectancy or suspected complicated urinary infection, large sized Malecot catheters should be considered.