Translation equivalents are widely used in bilingual research concerning word processing (e.g., Eddington & Tokowicz, 2013; Jouravlev & Jared, 2020) and second-language vocabulary learning (e.g., Bracken et al., 2017; Degani et al., 2014). Although translation norms exist in several languages, to date there are no Malay-English translation norms. This study presents the first Malay-English translation norms collected with highly proficient Malay-English bilinguals. Furthermore, the study investigates the impact of lexical characteristics on translation ambiguity. The forward translation (FT) task (N = 30) collected English translations for 1004 Malay words selected from the Malay Lexicon Project (Yap et al., 2010), and subsequently the backward translation (BT) task (N = 30) gathered Malay translations for 845 English words obtained from the FT phase. The data revealed a high prevalence of translation ambiguity in both translation directions. Specifically, verbs, adjectives, and class-ambiguous words were more translation-ambiguous than nouns. Furthermore, within-language semantic variability and word length were positively correlated with translation ambiguity, whereas word frequency only correlated with translation ambiguity in FT. Word length and word frequency of the source words and their translations were positively correlated. Intriguingly, only in FT were bilinguals with higher Malay proficiency more likely to provide accurate and dominant translations for the Malay words. These findings contrast with those reported in translation norming studies involving other language pairs. The translation norms provide a useful resource for bilingual language studies involving Malay-English bilinguals. [ABSTRACT FROM AUTHOR]