Conference interpreting is a professional activity in which are present several factors that cause regular physical and emotional stress in high intensity.The cognitive effort of the interpretation processwhich demands attention, memory, understanding of verbal and non-verbal messages, fluent translation and delivery in another language and the responsibility of performing all that in order to transmit the speaker's message as accurate as possiblerequires large amounts of mental energy.The psychological correlate of such mental stress is anxiety.Anxiety affects the perfomance of professional interpreters and can jeopardize or completely block learning in conference interpreting courses.This monography is about the role of anxiety in conference interpreting, especially its effects on learning in conference interpreting courses.Theoretical aspects are presented to explain how stress and anxiety affect interpreters physically and psychologically.A review of the relevant literature about the theme in the last decades is also presented.Finally, Chiang's work (2006) and his original construct "conference anxiety" are highlighted as well as the contributions it might bring to professional interpreters and courses of conference interpreting.