With english speaking population expanding rapidly due to increasing international communication, english is no longer spoken by native speakers alone. English is spoken in different regions around the world, developing into different variants reflecting local language and culture. When speakers in an international conference speak in non-native english, interpreters, unfamiliar to such varieties, may be challenged as unfamiliarity to specific variants is more likely to present difficulties in intelligibility and comprehensibility. Previous studies indicate that conference interpreters found unfamiliar accents challenging and difficult to interpret. This paper discusses stress factors for English-Korean interpreters presented by non-native english speakers, following the concept of ‘World Englishes,’ which refers to different varieties developed around the world reflecting cultural and linguistic norms of the region or society of speakers. This paper aims to identify previous researches that point to the challenges of interpreting performance in general, and world englishes, in particular, to develop a theoretical framework for analyzing specific difficulties experienced by English-Korean conference interpreters at the level of phonology, syntax, and processing effort