Childhood urinary tract infections (UTIs) can lead to renal scarring and ultimately to terminal renal failure, which has a high impact on quality of life, survival, and health-care costs. Variation in the treatment of UTIs between practices is high. To assess the cost-effectiveness of a maximum care model for UTIs in children, implying more testing and antibiotic treatment, compared with current practice in primary care in The Netherlands. We performed a probabilistic modeling study using Markov models. Figures used in the model were derived from a systematic review of the research literature. Multidimensional Monte Carlo simulation was used for the probabilistic analyses. Maximum care gained 0.00102 (males) and 0.00219 (girls) QALYs (quality-adjusted life-years) and saved 42.70 (boys) and 77.81 (girls) in 30 years compared with current care, and was thus dominant. Net monetary benefit of maximum care ranged from 20 to 200 for a willingness to pay for a QALY ranging from 0 to 80,000, respectively. Maximum care was also dominant over improved current care, although less dominant than to current care. This study suggested that maximum care for childhood UTI was dominant in the long run to current care, meaning that it delivered more quality of life at lower costs. Nevertheless, making firm conclusions is not possible, given the limitations of the input data.