Vocabulary knowledge plays a very important role in perfecting communication skills and acquiring a second language. In the absence of proper grammar, communication can still be achieved through the use of words or phrases. However, the lack of sufficient vocabulary is a challenge for students to enhance their overall language proficiency. The primary aim of this study is to determine the efficacy of mind mapping in instructing English vocabulary to first-year non-English majored students at Dong Nai Technology University. The sample for this study consisted of 122 students, with 52 male and 70 female, between 18 and 19 years old. This study utilized a combination of quantitative and qualitative research approaches, specifically questionnaire and observation. The results demonstrated the efficacy of mind mapping because it helped students improve their learning spirit and attitude, practice teamwork and presentation skills, and enhance vocabulary memorization as well.