Despite its importance for their academic achievement, many English Language majors find syntax a challenging subject matter, causing many syntactic inadequacies in their oral and written examinations. Tree diagrams have been used in syntactic analysis because of their distinct advantages in syntactic representation and organization. Computer-based tree diagrams could provide a useful means to visually communicate students' understanding of syntactic concepts, providing a wide range of affordances. This study investigated the effect of using TreeForm on enhancing English Language majors' EFL syntactic competence. Participants (N = 30) were second-year students in the Department of English Language and Literature, Faculty of Archaeology and Languages, Matrouh University, during the first semester of the 2022-2023 academic year. They were randomly divided into two groups: a control group (n = 15) which received traditional instruction and an experimental group (n = 15) which used TreeForm for six weeks. An EFL syntactic competence test was developed and administered after experimentation. Additionally, semi-structured interviews were conducted to explore students' perceptions of using TreeForm in enhancing their syntactic skills. During the experiment, students created syntax trees using the TreeForm features to analyze the assigned sentences applying the phrase structure rules, peer-reviewed, edited, and saved them for publication and use in other assignments. Results revealed that the experimental group significantly outperformed the control group in EFL syntactic competence. Thus, using TreeForm had a positive effect on enhancing English Language majors' EFL syntactic competence. The students also had largely positive perceptions toward its use. Such results suggest that TreeForm might be used to promote syntactic competence among EFL learners.