The paper investigates, through a questionnaire survey, interpreting students’ and professional interpreters’ perception of how well they perform when interpreting simultaneously into their A language vs. into their B language. The research revealed considerable differences between the professional interpreters’ and trainee interpreters’ views on this issue. Professionals generally felt that they performed better when working into their mother tongue, while only half of the students felt the same and 26% thought they worked better into B. In conclusion, hypotheses as to what factors can be responsible for this discrepancy are put forward, and the author expresses her support for A-B interpreting training aimed at preparing interpreting students for the needs of the market.