Given the complexity of spoken interaction, acquiring conversation skills has been difficult for most EFL learners, and as EFL classrooms largely depend on hypothetical scripted material, learners lack explicit exposure to naturally occurring language essential for real-life interaction. This paper reports on a quasi-experimental study aiming at assessing the impact of conversation analysis-(CA) informed language-in-(natural)-talk log assignments on the development of Thai EFL learners’ conversation skills. Eighty-eight second-year undergraduates at a university in southern Thailand took part in the study. As part of a monitored self-study task, the participants completed ten language-in-talk log assignments with self-selective use of audiovisuals available online. The quantitative data was collected using pre-and post-test role-plays. The qualitative data was assessed through completed log assignments, close analysis of the role-plays, and written interview for data triangulation. The findings suggested that the log assignment intervention significantly enhance participants’ conversation abilities, including turn construction, turn delivery, and the sequential organization of turntaking. The qualitative results also show that via CA-informed requirements of the log assignment, students became more aware of conversation mechanisms and language use in real-life interaction. This paper recommends that language-in-talk log assignments be incorporated into existing EFL conversation lessons.