This paper revisits the effect of lexical ambiguity in word recognition, which has been controversial as previous research reported advantage, disadvantage, and null effects. We discuss factors that were not consistently treated in previous research (e.g., the level of lexical ambiguity investigated, parts of speech of the experimental stimuli, and the choice of non-words) and report on a lexical decision experiment with Chinese nouns in which ambiguous nouns with homonymic and/or metaphorical meanings were contrasted with unambiguous nouns. An ambiguity advantage effect was obtained--Chinese nouns with multiple meanings were recognized faster than those with only one meaning. The results suggested that both homonymic and metaphorical meanings are psychologically salient semantic levels actively represented in the mental lexicon. The results supported a probability-based model of random lexical access with multiple meanings represented by separate semantic nodes. We further discuss these results in terms of lexical semantic representation and how different experimental paradigms result in different ambiguity effects in lexical access.