<p>Electrophysiological studies of visual word recognition rarely take account of differences in participants’ language skills. However, characteristics such as orthographic knowledge, vocabulary size, and reading experience can significantly influence these processes. The present study analyzed event-related potentials (ERP) recorded during passive reading of words with both correct and incorrect spellings. The first experiment (<i>N</i> = 26) assessed orthographic knowledge, while the second (<i>N</i> = 26) assessed vocabulary size and reading experience. In the first experiment, the orthographic effects of the P200 (high amplitude for correctly spelled words) and N400 (high amplitude for erroneously spelled words) components were observed only in participants with high levels of orthographic knowledge. In the second experiment, P200 amplitude was greater for correctly spelled words in the high-vocabulary group and for incorrectly spelled words in the low-vocabulary group. N400 effects varied in terms of topography across participants with different reading experience: in less experienced readers they were seen in the fronto-central areas, while in more experienced readers, they were seen in the left temporo-occipital region. No associations with participants’ language skills were observed for the late P600 wave. Thus, orthographic knowledge, vocabulary size, and reading experience predominantly influence the more automatic stages of orthographic processing, which is apparent as modulation of the P200 and N400 components. The data obtained here emphasize the importance of taking account of individual differences in language skills in studies of visual word recognition.</p>