We evaluated the age at which boys with a history of posterior urethral valves after no or minimal anticholinergic medication achieve urinary continence and the factors contributing to continence. We reviewed the hospital records of all males treated for posterior urethral valves at a single institution between 1990 and 2008. Continence was considered to have been attained if no weekly wetting episodes occurred. We evaluated the influence of patient characteristics, including reduced kidney function and primary ring type ureteral stoma, on age at which continence was achieved. A total of 76 patients were assessed. Achievement of daytime and nighttime urinary continence was markedly delayed in patients (mean ± SD age 5.5 ± 3.3 years and 5.4 ± 3.0 years, respectively) compared to the reference population (2.3 ± 0.5 and 2.9 ± 1.2, p <0.001). Increased serum creatinine levels at age 5 years were associated with later daytime and nighttime continence (mean ± SD 6.0 ± 3.2 and 5.5 ± 2.6 years, respectively, vs 4.1 ± 2.3 and 3.7 ± 1.4 years, respectively, in patients with normal serum creatinine, p ≤0.05). Prenatal or neonatal diagnosis of posterior urethral valves was associated with significantly delayed achievement of daytime continence compared to cases diagnosed later (mean ± SD 5.9 ± 3.6 vs 4.1 ± 1.8 years, p = 0.02). Patients with high nadir serum creatinine and vesicoureteral reflux initially also were at increased risk for urinary tract infections (p = 0.003 and p <0.001, respectively). Patients with posterior urethral valves achieve daytime and nighttime urinary continence significantly later than their healthy peers. Prenatal or neonatal diagnosis and high serum creatinine are associated with later attainment of continence.