Objective: To determine the efficacy and safety of holmium:YAG laser lithotripsy in children with ureteric calculi.Patients and methods: This is an observational study conducted on 104 children (61 males & 43 females) with upper,middle and lower ureteric stones for whom 128 laser ureteroscopies were done for management of urinary tract stones at Urology Department, AboulRiche children's Hospital,Cairo University during the period from March 2012 to May 2013.The age of patients in this study ranged from 6 months to 12 years old with a mean age of 4.7 ± 3.4 years (median 3.75 years).The longest diameter of the stones varied between 5mm and 20mm while the mean longest diameter was 11.0 ± 3.5 mm (median 10.0 mm).The most common site for stones was the lower ureter (56 cases) followed by the upper ureter (48 cases) then the middle ureter (24 cases).Semirigid 7.3f &9.5f uretroscopes were used and the HO:YAG laser energy delivered at 0.5-2.7J and 10-20Hz.Results: In our study there were 24 cases of failure, access failure in 16 cases(only in children less than 2yrs old), stone migration in 6 cases (4.7%) (only in patients ranged from 4 to 12 years with upper ureteric stones ) andextravasation in 2 URS in small ureters and stones more than 15mm.Complications were encountered in 66 procedures, There was no ureteralavulsion, bleeding or hematuria requiring blood transfusion or septic complications.The highest failure rate was reported in children ≤2 years old,upper ureteric stones and in stones >15mm (57.1%). Laser lithotripsy was successful in 104 ureteroscopies (81.25%) while it failed in 24 ureteroscopies (18.75%). After multivariate analysis Failure of dilatation and extravasation were detected only in children <2 years old. Extravasation was significantly higher in smaller ureters and cases with stone size >15 mm. Stone migration was significantly higher in upper ureteric stones.Conclusion: Holmium:YAG laser lithotripsy is an efficient and safe treatment for ureteric calculi in children. Complications were higher in children younger than 2 yrs, upper ureteric stones and stones size more than15mm while the highest failure rate was reported in children ≤2 years old,upper ureteric stones and stones more than 15mm.