Abstract Three auditory lexical decision experiments were conducted which investigated how morphological structure is represented in the lexicon. The first experiment showed that morphological relationships can be represented independently of semantic relatedness. A large facilitatory priming effect was found for morphologically related words that were not semantically related (e.g. submit, permit). Significant priming was not found for words that were simply phonologically related (e.g. balloon, saloon). The second and third experiments indicated that suffixes do not have lexical representations that can be primed during lexical access; morpholgical priming was not found between words that shared a suffix (e.g. joking, typing). Formal models which propose separate lexical entries for affixes are not supported. Finally, phonological priming was observed when words shared a final syllable but not when they simply shared final segments. Models of word recognition which include a level of syllabic representa...