The goal of this classroom action study is to increase the vocabulary of Vietnamese EFL university students by utilizing Kahoot! in the teaching and learning process. Eleven undergraduate Vietnamese students majoring in Information Technology in a university in the south of Vietnam took part in the study. The two-cycle Kemmis and McTaggart (1988) model was used. The investigator employed assessments for learners and surveys for educators to gather information, investigate if including Kahoot! may enhance students' vocabulary acquisition, and ascertain the viewpoints of educators on the benefits and drawbacks of their involvement. The results show that learners' vocabulary performance has improved. Teachers' feedback also shows that the Kahoot! application has increased student engagement in several ways, most notably by creating an enjoyable learning environment where students may practice both individually and in groups. It is reported that Kahoot! is easy to use and convenient. Technical issues and time management are a few of the drawbacks mentioned. The study's findings could be useful in helping teachers implement changes in their classrooms as well as serving as a resource and source of inspiration for academics and researchers with related fields of study. [For the complete proceedings, see ED672804.]