This article focuses on the use of conversation analysis (CA) to help teaching interactional competence in English to adult second language learners from lower to intermediate levels. To set the context, this article gives a brief overview on the use of CA in second language research as well as considering the construct of interactional competence in second language teaching. Based on classroom research, the article demonstrates how CA applied in the second language classroom was effective initially in raising students' awareness of both the mechanisms and norms of spoken interaction, and also eventually in helping them to become analysts of conversation and more effective conversationalists. To better understand what CA concepts needed to be taught a conversation analysis of the students' undirected conversations was undertaken revealing interactional problems not noticed through traditional methods of investigation. It is therefore suggested that a CA-informed pedagogical approach can help to teach interactional competence or competencies, by using materials designed for that purpose. (Contains 1 figure and 16 notes.)