Abstract: Vocabulary acquisition is central to developing proficiency and competency in any language learning skill. However, many students face challenges in learning and retaining lexical items due to a lack of effective learning strategies. Therefore, the purpose of this study was to investigate the potentially significant effects of mind mapping on the vocabulary development of EFL high school students. The research design employed a combination of quasi-experimental research design, involving the participation of 95 Grade 12 EFL students from a high school in Thai Binh Province, Viet Nam. These participants were divided into two groups: the control group and the experimental group.