The effect of orthographic transparency on letter position encoding was investigated using a visual search task given to skilled readers of English (a deep orthography) or Greek (a transparent orthography). Two groups of younger participants, matched for age and education, were monoscriptal in English, or biscriptal in Greek and English. Two groups of older participants, matched for age and education, were monoscriptal in either English or Greek. All participants were given a letter search task in which they were required to detect the presence of a previously cued letter target within a random five-letter string. Stimuli were either letters shared by both orthographies or letters specific to either English or Greek. Results showed a significant effect of orthographic transparency on search performance. When searching for letters of their native orthography, all reader groups showed facilitated identification of target letters appearing in the first compared with the second position, consistent with both parallel and serial processing. In contrast, only the two groups of monoscriptal English readers showed significantly facilitated identification of letter targets in the fifth relative to the fourth position, consistent with parallel processing. These results suggest that letter position encoding is adaptive to the structure of the orthography to which a reader is exposed during reading acquisition. (Contains 2 figures, 2 tables and 1 footnote.)