The issue of regular-irregular past tense formation was examined in a cross-modal lexical decision task in Modern Greek, a language where the orthographic and phonological overlap between present and past tense stems is the same for both regular and irregular verbs. The experiment described here is a follow-up study of previous visual lexical decision experiments (Tsapkini, Kehayia, & Harema, 2002) that also addressed the regular-irregular distinction in Greek. In the present experiment, we investigated the effect of input modality in lexical processing and compared different types of regular and irregular verbs. In contrast to our previous intra-modal (visual-visual) priming experiments, in this cross-modal (auditory-visual) priming study, we found that regular verbs with an orthographically salient morphemic aspectual marker elicited the same facilitation as those without an orthographically salient marker. However, irregular verbs did not exhibit a different priming pattern with respect to modality. We interpret these results in the framework of a two-level lexical processing approach with modality-specific access representations at a surface level and modality-independent morphemic representations at a deeper level.