Fadlia Ismail, 2023. Student’s ID: 321419006. Structure Parallelism in Academic Writing: A Review of EFL Students’ Undergraduate Thesis. Undergraduate Thesis. English Language Education Study Programme., Faculty of Letters and Cultures, Universitas Negeri Gorontalo. Principle Advisor: Zulkifli Tanipu, S.Pd., M.A., Ph.D. Co-advisor: Muzdalifah Mahmud, S.Pd., M.Pd. In creating a work of writing there are several things that students must be aware of attention and also challenges in writing, especially about parallel structure. This research discusses about the parallel structure in EFL students’ undergraduate thesis. Both parallel and unparallel structure are seen in this study on students’ writings. Descriptive linguistics is used as a method of this research. The data are linguistics features: word, phrases, and clauses, taken in the part of students’ class of 2015 that graduated in 2022 period. The objective of this research is to analyze how the structure of parallelism in EFL students’ undergraduate thesis. The significance of this research theoretically can be used as a reference to see the ability of students’ academic writing, and maximize the teaching of parallelism structure through writing and grammar courses. Practically can be also help the design tools and the instructional practices that are specifically designed to address the difficulties that EFL students encounter while writing for academic purposes. As a result, the part with parallel structure is more dominant than the unparallel structure. This shows that the undergraduate thesis of class 2015 students who graduated in the 2022 period is good in terms of parallel structure. Keyword: parallel structure, academic writing, EFL students, undergraduate thesis