This study investigated the relative extent to which developing readers (6- and 9-year-olds) of English (deep) or Greek (transparent) orthography exhibit serial and exterior letter effects in letter position encoding. Participants were given a visual search task that required detection of a pre-specified target letter within a random five-letter string. Stimuli comprised letters either specific to English or Greek, or shared by both orthographies. For native letters, all readers showed significant initial-letter facilitation. In contrast, final-letter facilitation was shown only by English children. Furthermore, Greek 9-year-olds showed significantly more left-to-right facilitation than English 9-year-olds. These results suggest that letter position encoding is adaptive to the nature of the orthography acquired during reading development.