Employing conversation analysis as a research technique, this study investigates the ways that unintelligibility is accounted for and overcome within a therapeutic encounter between an individual with aphasia and dysarthria and his clinician. The results emphasize the collaborative nature of intelligibility negotiation and demonstrate how both the individual with the impairment and his clinician employ various interactional strategies and knowledge resources to turn unintelligibility into intelligibility so that the therapeutic encounter may continue.