Some institutional settings, such as therapeutic or counselling settings, involve normative models, theories or quasi-theories concerning professional-client interaction. These models and theories can be found in professional texts, in training manuals and in written and spoken instructions delivered in the context of professional training or supervision. In this article, we would like to call these models and theories 'stocks of interactional knowledge' (SIKs). Our aim is to explore the possibility of a dialogue between conversation analysis and such SIKs. Based on research on medical and counselling settings, we discuss the different relationships that CA and such interactional theories may have. We propose that CA findings may (i) falsify or correct assumptions that are part of an SIK; it may (ii) provide a more detailed picture of practices that are described in an SIK. (iii) CA may also add a new dimension to the understanding of practices described by an SIK, or (iv) provide the description of practices, not provided by a very abstract or general SIK.