This study aims to find out whether there is a significant relationship between Interpreting Self-Efficacy (ISE) andtranslation/interpreting performance levels. For this purpose, 144undergraduate students at a Seoul-based university (74 translationstudents and 70 interpreting students) were asked to fill in Lee’s(2014) ISE questionnaire, and their responses (i.e. ISE scores)were then statistically compared with their translation andinterpreting performance scores (summative assessment scoresassigned by one translator trainer and three interpreter trainers). The analysis shows that there are strong positive correlationsbetween ISE and interpreting performance scores, while there areno significant correlations between ISE and translation scores.