Word to be produced passes through several encoding processes, which time course has been verified by different psycholinguistic studies. The age, at which the words were learned, known as Age of Acquisition (AoA), is an important factor influencing picture naming speed. The purpose of this study was to analyse the reaction times and the error rates in French speaking children aged 7-12 years (N = 29) picture naming, as well as to investigate, using Electro-encephalography (EEG), where in the temporal distribution of word production processes do the effects of AoA fall. Participants' age, AoA and interaction between both affected reaction times (RTs) and error rates.