This study aimed to explore the types of pronunciation errors that student interpreters make in pronouncing foreign Proper Nouns during English-Arabic and Arabic-English Liaison Interpreting, the pronunciation error strategies that students utilize when they encounter unfamiliar Proper Nouns in media discourse, and the factors that affect students' incorrect pronunciation of foreign Proper Nouns. A corpus of foreign Proper Noun pronunciation errors was collected from interpreting tests and in-class practice. Error analysis showed that students have difficulty identifying and discriminating one or more phonemes in foreign Proper Nouns such as "Rio di Janeiro," "Paraguay," "Abuja," "Davos," "Scandinavia," "Missouri," "Helsinki," "Crimea," "Al Gore," and "Yuan," whether such words were heard in English or Arabic. Whenever the students heard an unfamiliar Proper Noun, they produced (made up) nonsense words that rhyme with the unfamiliar source words as in *Dagos, *Dados, *Dabos which they provided for "Davos"; *lizouri, *rozouri, *kansouri, *mansouri instead of "Missouri"; and *Scinavia for "Scandinavia." Sound analogy was also used in producing equivalent for unfamiliar Proper Nouns. Volcanoes and *burkini were provided as equivalents for "Balkans" and *NADO for "NATO." They reduced, i.e., deleted part of the Proper Noun, whether it is a vowel, consonant or even a syllable as in *Buja instead of "Abuja," "United" *State, *Izheimer, *Philippine, *Parkins, *Bloomber probably because of the length of the words and poor short-term memory. Phonemes were changed and substituted by a longer or shorter vowel, by another consonant or another syllable as in Dracula /dracola/, /gri:k/; Sergey Lavrov /sergi la:vro:v/; *snab shat, *Uzbakistan, *foks fagon, Ukraine /[near-close back rounded vowel]kr[voiced postalveolar fricative]:rI[schwa]/, /sinofa:rm/. The Arabic pronunciation was retained and overgeneralized in "Eiffel Tower" /i:f?l/ or /i:v?l/, *Ardoghan, *Anadol, and *Athina. A vowel was inserted to break the consonant clusters in *Beligrade, *Bangaladesh, *Barazil, *Danimark, *Kazakhistan, *Uzbakistan, *Shangahai, *Tarafalgar. Syllables were reversed in *Serbrenica and *ALESCO. Most pronunciation errors in interpreting are attributed to lack of knowledge of Proper Nouns commonly occurring in the media. Knowledge of the similarities and differences in Proper Noun pronunciation in English and Arabic and extra practice using online videos, podcasts, mobile apps, and TED Talks are needed in Liaison Interpreting instruction.