Analysis of results and complications of retrograde rigid ureterorenoscopies (URS) performed in our unit between August 1985 and June 1990. Our series includes 122 URS performed in 106 patients: 68% female and 32% male. A rigid ureteroscopy Storz 11.5 Ch was used. URS indications were: 72% treatment of ureteral lithiasis, 14% diagnosis, 7% treatment of ureteral tumores and 3% other reasons. Treated lithiasis were predominantly located in the pelvic ureter. Overall success in the treatment of lithiasis was 92.86% in "primary" lithiasis, and 71.43% in post-ESWL. URS allowed us to resolve troubles of differential diagnosis in 93.75% of cases. With a complications rate of 19.7%, only 3.28% were considered relevant.