This systematic review aims to investigate the effectiveness of text structure instruction (TSI) on students' expository writing and, using the insights obtained from the review, to develop theoretical frameworks and instructional procedures for TSI that will mainly serve the types of learners targeted by the present study. With this in mind, inclusion and exclusion criteria were set, and 14 experimental and quasi-experimental studies conducted on primary school students were selected. The review revealed that TSI could improve the inclusion of main ideas in written summaries and enhance the quality of expository text structure writing. Specifically, it can improve students’ ability to identify the main ideas and supportive details from the source text. Moreover, the study revealed a lack of consistent reporting on the fidelity of implementation and comprehensiveness, which are limitations of the reviewed studies. The review also revealed that an explicit TSI that integrates reading and writing skills and encourages the gradual release of student responsibilities during the writing process may enhance the ability of primary school EFL learners to write expository texts.