OBJECTIVE: To assess the baseline ability of pediatric residents to successfully perform a lumbar puncture (LP) and to evaluate the impact of an educational intervention on this skill in both a simulated and clinical environment. METHODS: An experimental group of first-year residents and a control group of second-year residents were enrolled in a prospective nonrandomized intervention study. Knowledge and skill at performing LPs were assessed using a written and a simulated LP test. The experimental group was tested at the start of their residency and then received the educational intervention. They were retested 6 months later. The control group did not receive the educational intervention and were tested at the start of their second year. The outcomes of clinical LPs performed by the 2 groups were also recorded. RESULTS: The experimental group showed significant improvement on both the written and the simulated LP test after the educational intervention. When compared with the control group, they performed the simulated LP significantly better as measured by the number of correctly performed steps. Both groups performed a low number of clinical LPs. CONCLUSIONS: After an educational intervention, pediatric first-year residents performed a simulated LP better than a group of second-year residents who had greater clinical LP experience. The low number of clinical LPs performed limits our ability to determine the educational intervention's impact in the clinical setting and reinforces the concern that recent changes to pediatric residencies may negatively impact residents' procedural experience.