The study aimed to conduct a systematic literature review to identify the trends, impacts, and challenges of mobile microlearning (MML) research. Using five academic databases from the fields of social science, engineering, and medical science as search sources, 26 scholarly articles, published between 2015 and 2020, were retrieved. The study applied a content analysis method to analyze and synthesize the data with three focal points: (a) research purposes and publication sources; (b) research settings, including learning domains, contexts, research methods, measures, and participants; and (c) research outcomes, advantages, and challenges of MML based on the reviewed literature. Results indicated that the mixed-method approach has become a trend in MML studies and MML has been widely applied in both formal and informal settings, especially in the just-in-time workplace learning. In terms of advantages, MML not only enhanced learners' achievement and motivation but also improved skills and knowledge retention. Some deficiencies of MML that were identified included the need for further investigation on meaningful designs of microcontents to fit into small screen mobile devices and issues of usability. The paper discusses implications for researchers and practitioners.