Objectives. To describe our recent experience using a 6.9F cytoscope in the fulguration of posterior urethral valves (PUVs) in premature neonates and distal ureteroscopy with stone extraction in children.Methods. Fulguration of PUVs was performed in 3 premature neonates born at 34 to 36 weeks' gestation with weights of 2480 to 2900 g. The PUVs were fulgurated during a single endoscopic procedure using a 6.9F cystoscope and a 3F bugbie electrode. In addition, 11 children (8 girls, 3 boys; mean age, 11.1 years; range 5 to 16) with symptomatic calculi underwent 15 distal ureteroscopic procedures using the 6.9F cystoscope.Results. In the neonates with fulguration of PUVs, vesicostomy, the only reasonable alternative, was avoided, and each infant now voids with an excellent stream 3 to 16 months later, without evidence of stricture or residual valves. In the children with distal ureteroscopy, the ureteral calculi were retrieved using a 3F four-wire stone basket. With one exception, distal ureteroscopy was performed without dilation of the ureteral orifice. Extracorporeal shock-wave lithotripsy (ESWL) was not recommended because of stone position and difficult radiographic visualization. Nine children were rendered stone free with one procedure. Two procedures were required in 1 child and three in another. In both cases, ureteral edema was present and the stone was embedded in the ureteral wall. One child underwent separate procedures for bilateral calculi. In all cases general anesthesia was used with a mean duration of 63 minutes (range 28 to 96). Temporary ureteral stenting was performed in 10 (93%) patients, and 9 (81%) were discharged home on the same day or the next morning. A mean follow-up period of 8.5 months (range 0.5 t 22) has failed to show any problems related to ureteral stricture or injury.Conclusions. Endoscopic fulguration of PUVs is now possible in small neonates and is minimally invasive compared with vesicostomy. Distal ureteroscopy with stone retrieval should be considered in children, especially those with calculi that are not suitable for ESWL.