The acquisition of new orthographic representations has been systematically found as a fast and accurate process in monolingual readers. The present study aims to extended this research to biliterate and bialphabetic population, addressing the impact of phonological inconsistencies across the native (L1) and second (L2) alphabet. Naming latencies were collected from 50 Russian-English biliterates through a reading-aloud task, in which familiar and novel words were repeatedly presented across 10 blocks. The stimuli were equally divided in three script conditions: Cyrillic, Roman (in both cases, using script-specific graphemes) and ambiguous (using graphemes common to L1 and L2 alphabets, and thus phonologically inconsistent). Linear mixed-effects modelling revealed differences in the process of orthographic learning depending on the script. Thus, although naming latencies for novel and familiar words in the ambiguous condition were matched along the training, this effect was much faster in conditions of phonological consistency. Nonetheless, post-training outcomes of learning revealed similar recall and recognition performance in familiar and trained words regardless of the script. Overall, our results indicate that phonological inconsistency interferes with the decoding of novel words but does not prevent the efficient achievement of orthographic representations in biliterates.