CLIL (Content and Language Integrated Learning) incorporates content acquisition and language instruction, allowing students to develop linguistic competencies while engaging with particular topics. This research aims to investigate the effectiveness of CLIL activities in enhancing students' vocabulary, as well as to explore students’ views of engaging in CLIL activities for their learning process. The participants consisted of 21 primary school students with diverse levels of English ability. The study employed a mixed-methods research approach, combining a quasi-experimental study (one-group pre-test and post-test) with a survey. The results indicated that CLIL activities notably improved students’ vocabulary mastery, with post-test scores (Mean: 60,38) surpassing the average pre-test scores (Mean: 58,28). In response to the students' perceptions of their experiences, among 21 students, 15 (71%) indicated that CLIL activities enhanced their interest in English and science. In this study, CLIL activities were carried out by incorporating singing, engaging in games such as flashcards and QNA, and facilitating group discussions. The CLIL activities offer significant contexts for language application, facilitating the effective acquisition of new vocabulary for students. The students demonstrated enhanced vocabulary test scores as a result of the learning activities. The findings indicate that CLIL-based learning significantly enhances students’ vocabulary, and students express a favourable perception of this approach. Educators should incorporate CLIL activities into their instructional methods to create a vibrant and engaging learning environment. Future investigations could delve into the implementation of CLIL across various educational settings and disciplines to fully harness its potential advantages.