The adult lexicon is organized among many representational dimensions that encode phonological, semantic and perceptual links among words. Priming studies that use behavioral, eye-tracking and electrophysiological measurements highlight the interactive and dynamic nature of lexical processing and representation in the adult lexicon. These studies suggest that word recognition routinely involves simultaneous access to other words that overlap with a spoken word on phonological (Slowiaczek et al., 1987; Marslen-Wilson & Zwitserlood, 1989), semantic (Meyer & Schvaneveldt, 1971) or other perceptual dimensions (Dahan & Tanenhaus, 2005; Huettig & Altmann, 2007). While these studies provide valuable information about the mechanisms guiding lexical retrieval and the factors underlying lexical organization in the lexicons of adult college-educated individuals who know many thousands of words, it is debatable the extent to which these findings can be extended to our understanding of early lexical processing in young children. On the one hand, differences in general cognitive abilities, linguistic experience and language-related knowledge in young children and college-educated adults could imply drastic differences in the way words are linked in developing and mature lexicons. On the other hand, once a word has an entry in the mental lexicon, how many or which other words the child knows may be irrelevant, such that a) the structure of the developing lexicon is a miniature version of the adult lexicon, organized according to similar dimensions; and b) the processes guiding word recognition differ minimally across development. Adjudicating between these two proposals requires examination of the structure of the early lexicon and the processes guiding lexical processing in young children. How does this structure initially develop and change as the child’s knowledge grows over time? Does the organization of the early lexicon influence subsequent word learning and word processing? Understanding these questions has the potential to inform adult theories of psycholinguistic processing and highlight important processes in early vocabulary development. This chapter will attempt to answer these questions against the background of the literature to date whilst also sketching paths for future research on the topic.