Objective To compare the outcome of laparoscopic with open partial nephrectomy for duplication anomalies. Methods A total of 64 patients with mean age of 17 months were divided into 2 groups.Open group consisted of 36 patients,and laparoscopic group consisted of 28 patients.In open group,there were 19 boys and 17 girls,15 cases were of ectopic ureter,18 of ureterocele,2 of vesicoureteral reflux (VUR) and 1 of ureteropelvic junction obstruction.Mean age was 18 months.In laparoscopic group,there were 18 boys and 10 girls,9 were of ectopic ureter,16 of ureterocele and 3 of VUR.Mean age was 1 6 months.There were no significant differences in age and diseases.Results There were 2 conversion to open surgery in laparoscopic group and no other intra-operative and post-operative complications in 2 groups.Mean duration of operation was 2.5 h for open group,the difference of pre- and post-operation hemoglobin was 2.64 g,the volume of drainage was 91.4 ml,the time of drainage was 4.2 d and mean hospital stay was 19.3 d.In Iaparoscopic group,the figures were 2.9 h,1.45 g,55.4 ml,3.4 d and 14.3 d,respectively.The differences of the figwres were significant between the 2 groups (P＜0.05). Conclusion Laparoscopic partial nephrectomy is effective and safe for the treatment of duplicated kidney with a dysfunctional moiety.