The study reported here investigated the effects of recasts on L2 development in terms of promoting EFL learners' accuracy in using English articles during mobile-mediated audio and video interactions. Fifty-two Iranian EFL learners were randomly assigned into two audio and video recasts conditions as well as two audio and video control groups. During five treatment sessions, the participants in the audio recasts group performed several online communicative tasks via their smartphones with their interlocutor and received recasts in response to their errors during audio interactions. The participants in the video recasts group performed the same tasks and received recasts during video interactions. The analyses of the learners’ post-test scores indicated the benefits of recasts provided during both audio and video interactions for L2 development although recasts provided during audio interactions proved to be more effective than recasts delivered during video interactions. The analyses of learners’ perceptions of recasts and also their responses to recasts revealed that the learners had more accurate perceptions of audio recasts and that the participants produced more target-like modified output in response to audio recasts compared to the video recasts. The implications for language teaching, especially technology-based and distance education, will be discussed in the study.