Classroom instruction provides a limited amount of quality speaking practice for language learners. Asynchronous multimedia-based oral communication is one way to provide learners with quality speaking practice outside of class. Asynchronous multimedia-based oral communication helps learners develop presentational speaking skills and raise their linguistic self-awareness. Twenty-two peer-reviewed journal articles studying the use of asynchronous multimedia-based oral communication in language learning were reviewed, (1) to explore how asynchronous oral communication has been used to improve learner speaking skills, and (2) to investigate what methodologies are commonly used to measure and analyze language gains from using asynchronous multimedia-based oral communication to improve learner speaking skills. In this study we present three principal findings from the literature. First, asynchronous multimedia-based oral communication has been used in conjunction with a variety of instructional methods to promote language gains in terms of fluency, accuracy and pronunciation. Second, the methods found in this review were technical training, preparatory activities, project-based learning, and self-evaluation with revision activities. Third, the majority of previous studies demonstrating the effectiveness of these methods have relied on learner perceptions of language gains rather than on recordings of learner speech.