Teaching ought to be based on research and scholarship, which implies a theoretical framework or theoretical foundation. In short: also when teaching simultaneous interpreting, which is the topic under discussion in this article, a theory is needed. The question which arises then is: do we have such a theory of simultaneous interpreting? Is it necessary to envisage it on a separate disciplinary footing or is there enough common ground between translation and interpreting for a shared theoretical base? In this paper the author argues for and outlines an integrative theoretical framework and suggests where and when in the curriculum as well as if and how in the classroom such a theory is to play a role in the training of professional conference interpreters.