Purpose: The purpose of this analysis was to review our initial experience of pediatric robotic-assisted pyeloplasties (RALPs). Our case series spanned a 7-year period (January 2004-February 2011). The initial 20 cases were reviewed retrospectively (RG group), and the later 20 cases were seen prospectively (PG group). We compared outcomes between these two groups. Subjects and Methods: After institutional review board approval, all charts were reviewed, and outcomes were based on postoperative imaging. For continuous variables t tests were performed, and for categorical variables Fisher's exact tests were performed. Statistical analysis was performed with SPSS version 17.0 software (SPSS, Inc., Chicago, IL). Results: There was no significant difference in demographics between the two groups. Median age at time of surgery was 64 months (PG) and 36 months (RG). Narcotic use was statistically similar among the groups when comparing median morphine intravenous equivalent per kilgram. Mean follow-up was 15.6 months (PG) and 41.8 months (RG). Postoperative imaging was stable or improved in 95% (PG) and 100% (RG). RALP in 1 patient in the PG group failed and later required repeat surgery (5%). The only identified significant difference between the two groups was surgical time. Mean operative time was reduced by over an hour between the two time periods (230 minutes for PG, 297 minutes for RG [P < .01]). Conclusions: The experience in pediatric RALP is growing at our institution. As this experience grows, the primary outcome that has changed is faster operative times. This increased efficiency does not correlate with compromised outcomes. We continue enrolling patients in our prospective database to strengthen the power of our outcomes analysis.