This study assessed whether bilingual memory is susceptible to the extreme processing demands of professional simultaneous interpreters (PSIs). Seventeen PSIs and 17 non-interpreter bilinguals completed word production, lexical retrieval, and verbal fluency tasks. PSIs exhibited enhanced fluency in their two languages, and they were faster to translate words in both directions. However, no significant differences emerged in picture naming or word reading. This suggests that lexical enhancements in PSIs are confined to their specifically trained abilities (vocabulary search, interlingual reformulation), with no concomitant changes in other word-processing mechanisms. Importantly, these differences seem to reflect specifically linguistic effects, as both samples were matched for relevant executive skills. Moreover, only word translation performance correlated with the PSIs’ years of interpreting experience. Therefore, despite their tight cooperation, different subcomponents within bilingual memory seem characterized by independent, usage-driven flexibility.