ESL instructors across the world acknowledge the importance of vocabulary among their students which led them to experiment with many teaching approaches and language stimuli to find ones that are effective. In line with global technological advancement, the captioned video has become a key stimulus in facilitating vocabulary acquisition among second language learners. The use of technology is highly encouraged in the Malaysian education system to promote meaningful and active learning to accommodate, particularly, the young learners’ needs. By using highly interactive and visually stimulating materials, Malaysian teachers are expected to improve the alarmingly low proficiency in English among primary school learners. This study aims to investigate the effects of captioned videos on English vocabulary involving 44 participants of Year Four (age 10) and Year Five (age 11) at a rural school in Kapit, Sarawak. Using a pre-test-post-test quasi-experimental research design, the participants were divided into a treatment group and a control group. The data were analyzed using SPSS and it was demonstrated that participants from the treatment group outperformed the control group which suggests the effectiveness of captioned videos on vocabulary acquisition in an ESL setting. The results of the study serve as empirical evidence to guide policymakers in their professional decisions and as insights to other ESL practitioners in expanding their teaching repertoire.