The processes through which readers evoke mental representations of phonological forms from print constitute a hotly debated and controversial issue in current psycholinguistics. In this paper we present a computational analysis of the grapho-phonological system of written French, and an empirical validation of some of the obtained descriptive statistics. The results provide direct evidence demonstrating that both grapheme frequency and grapheme entropy influence performance on pseudoword naming. We discuss the implications of those findings for current models of phonological coding in visual word recognition.