Abstract Objective The growing multilingual population in the United States calls for culturally adapted norms for neuropsychological tools. Language testing, for example, is paramount in pre-surgical assessment in patients with dominant temporal lobe epilepsy. The Boston Naming Test (BNT) and the Auditory Naming Test (ANT) are frequently used in pre-surgical epilepsy evaluations; yet, while bilingual norms exist for the BNT, these are lacking for the ANT. To parse out how much of a bilingual patient’s language performance is accounted for by bilingualism versus language deficits, we studied whether there is a significant difference in ANT performance between bilingual and monolingual English-speaking epilepsy patients. Method Our sample of patients with localized epilepsy from the UCSF Epilepsy Center included 22 bilingual (English-dominant; non-dominant languages included Spanish, Arabic, Dutch, Taiwanese, and Japanese) and 61 monolingual English-speakers (39% female, M age = 36.3). All patients took anti-seizure medication and completed the ANT and BNT as part of a pre-surgical neuropsychological assessment. Results Compared to monolingual English-speaking patients, bilingual patients had significantly lower scores on the ANT (Bilingual M = −4.03 SD = 5.6, Monolingual M = −0.7 SD = 1.9; t(81) = 3.89, p < 0.001) and BNT (t(77) = 2.76, p = 0.007). This performance difference was significantly greater for the ANT than BNT (F(1,77) = 7.71, p = 0.007). Conclusion These results highlight the importance of considering multilingualism in neuropsychological assessments. This is especially needed for pre-surgical language mapping in epilepsy surgical candidates. Future research should establish bilingual normative standards for neuropsychological language-based tests such as the ANT.