The paper discusses factors which affect the general quality of consecutive and simultaneous translation from Polish into German. These factors are articulation and intonation mistakes, as well as extralinguistic factors such as improper breathing, too high pitch nasality, muscle tension in the oral cavity and larynx. Most of these phenomena are caused by stress and fear of speaking in public, commonly referred to as stage fright. Exercises aiming at eliminating the consequences of stress, and thus articulation and intonation mistakes, have been described on the basis of experience from many years of working with students of German Philology and Translation Studies. Reducing negative factors in the area of pronunciation and stress control enhance the quality of translation and the degree of understanding the content of translated message. The problems described in this paper show necessity of pronunciation classes and logopedy in the course of interpreters’ training.