This paper discusses findings of a study conducted on Australian Sign Language (Auslan)/English interpreters in a university lecture, with consideration given to factors that influenced the interpreters’ omissions. The hypothesis of the study was that interpreters would make recourse to omissions both consciously and unconsciously, depending on their familiarity with the discourse environment and the subject matter. Through exploration of theoretical perspectives of interpreting and discourse studies, it is argued that interpreters use omissions as linguistic strategies for coping with the discourse environment. The findings of the study present interpreters with a new perspective on omissions in interpreting, which can be applied to both signed- and spoken-language interpreting.