Course materials play a vital role in the foreign language classroom. Relatively little attention has been paid, however, to analyzing the activities that foster oral interactional ability in course materials for English as a foreign language (EFL). For the purpose of this study, a coding scheme was designed that focuses specifically on the development of interactional ability. This was used to analyse the three most commonly used EFL course books for pre-vocational learners in the Netherlands. The analysis revealed that course books focus more on developing language knowledge than on developing the ability to use this knowledge in interaction, that interactional strategies practice is missing, and that interactional practice is limited to the personal and public context. We conclude that EFL course books lag behind current theories of second language acquisition (SLA) in the practical application of activities focused on developing interactional ability. Recommendations to strengthen the link between theory and practice are made.