Event-related potential (ERP) analysis associated with semantic priming is traditionally based on the comparison between experimental conditions of the mean amplitude values, which are within the range of the N400 component latency. In this study, we used a complete ERP dataset to examine whether middle- and long-latency components are modulated by semantic priming in school-age children. ERPs were recorded while normal children read pairs of words and decided whether the second word of the pair belonged to the same semantic category as the first word. We used nonparametric multivariate permutation analysis to compare whole ERP amplitude values between related and unrelated word pairs. We also obtained ERPs from a sample of children with poor reading skills (reading disabled children) to evaluate the effect of semantic priming in a population with known information retrieval failures. We found larger P200 amplitudes for responses to related word pairs compared to unrelated word pairs and larger N400 amplitudes for responses to unrelated word pairs compared to related word pairs in normal children. In contrast, children with reading disabilities did not exhibit any significant differences regarding either of these components. Thus, changes in the topographical distribution of ERP components over time might reflect the activation of several brain structures. These results suggest that semantic priming is a process that is not only associated with the N400 component.