It is well established that vocabulary size is related to efficiency in auditory processing, such that children with larger vocabularies recognize words faster than children with smaller vocabularies. The present study evaluates whether this relation is specific to the language being assessed, or related to general language or cognitive processes. Speed of word processing was measured longitudinally in Spanish- and English-learning monolinguals and bilinguals at 16 and 22 months of age. Speed of processing in bilinguals was similar to monolinguals, suggesting that the number of languages to which children are exposed does not influence word recognition. Further, cross-language associations in bilinguals suggest that the dominant language supports processing in the non-dominant language. These cross-language associations are consistent with general language and cognitive efficiency accounts in which the relation between word processing and knowledge relies on experience within a language as well as on general and cognitive properties of language learning.