The growing presence of multilingualism in contemporary cinema has intensified scholarly interest in how audiovisual translation (AVT) negotiates linguistic diversity across languages and modes. While previous research has examined the translation of multilingual films, comparative studies exploring how different AVT traditions render multilingualism across both dubbing and subtitling remain limited. Addressing this gap, the present study investigates the strategies employed in Persian and Russian dubbing and subtitling to represent multilingualism in English-language films. The corpus comprises the final two installments of the Mission: Impossible franchise, whose Persian and Russian dubbed and subtitled versions were subjected to comparative qualitative analysis. The findings reveal substantial cross-cultural and cross-modal variation in the treatment of multilingual elements. Russian AVT, particularly dubbing, demonstrates a stronger tendency to preserve and foreground linguistic heterogeneity through a wider range of translation strategies, whereas Persian AVT more frequently reduces or neutralizes multilingual cues. The results further suggest that differences in national dubbing traditions, audience expectations, and attitudes toward foreign-language presence shape translators’ decisions regarding the representation of multilingualism. In particular, the comparatively less conventionalized nature of dubbing in Russia appears to provide greater flexibility for retaining multilingual features and reproducing the linguistic complexity of the source text. By highlighting the interaction between translation mode, sociocultural context, and multilingual representation, the study contributes to current debates on audiovisual translation and the cross-cultural mediation of linguistic diversity in film.