OBJECTIVES: Posterior urethral valves predispose children to renal replacement therapy (RRT) and bladder dysfunction. Researchers of single-institutional series were unable to refine risk stratification because of rarity of the disease. We aimed to identify clinical variables associated with the risk of RRT and clean intermittent catheterization (CIC) in a large multicenter cohort study. METHODS: Children with posterior urethral valves born between 1995 and 2005 who were treated before 90 days of life at 5 children's hospitals were retrospectively reviewed. Outcomes included RRT and recommendation for CIC. Predictors and outcomes were assessed by using survival analysis. RESULTS: A total of 274 patients were managed for a median of 6.3 years, and 42 progressed to RRT. On survival analysis, 16% progressed to RRT by 10 years of age. RRT varied by the serum nadir creatinine level in the first year of life (SNC1) (log-rank P < .001). After stratifying by the SNC1, the estimated risk of progressing to RRT by 10 years of age was 0%, 2%, 27%, and 100% for an SNC1 of <0.4, an SNC1 of 0.4 to 0.69, an SNC1 of 0.7 to 0.99, and an SNC1 of >/=1.0 mg/dL, respectively. CIC was recommended in 60 patients, which translated on survival analysis to a risk of 26% by 10 years of age. CONCLUSIONS: Risk of RRT and CIC recommendation increased with age. The SNC1 strongly predicted need for RRT. These results allow for both improved family counseling and the potential for more appropriate screening and intervention strategies for those identified in higher-risk groups.