The technological developments of the twenty-first century have enabled the emergence of alternative teaching-learning models and instructional tools. One of the concepts brought about by such developments is mobile learning. The aim of this study was to test the effect of mobile learning on students' mathematics achievement. A systematic database search that included the Academic Search Complete, Education Resources Information Center (ERIC), EBSCO, JSTOR, ScienceDirect, Taylor & Francis Online, and Web of Science was carried out to examine peer-reviewed articles that met the inclusion criteria. A total of 22 quantitative research papers published between 2010 and 2020 were included in the meta-analysis. The results show that mobile learning has a medium-level positive effect (g = 0.476; p < .001; with a 95% confidence interval of 0.335-0.616) on students' mathematics achievement. Moderator analyses showed that the effect sizes were not significantly moderated by grade level and implementer, while content area was found to be a moderator. Based on the results, some suggestions are offered for future studies in designed learning environments.