This study investigates students’ mastery of vocabulary through teaching with CBeebies videos at a private junior high school in Aceh Besar. A total of 18 students were purposively selected to participate in a teaching treatment using CBeebies videos during their English lessons. The effectiveness of the CBeebies intervention in improving students' vocabulary acquisition was assessed using a paired t-test. This statistical test compared the means of the pretest and posttest to evaluate whether the difference between them was statistically significant. The results revealed that the calculated t-statistic (5.60) exceeded the critical t- value (2.11) at 17 degrees of freedom with a significance level of 0.05. This indicates that the null hypothesis was rejected, confirming a statistically significant improvement in students' vocabulary scores. Furthermore, the reduction in standard deviation from 14.69 (pretest) to 13.18 (posttest) suggests more consistent performance among students after the intervention. These findings demonstrate that CBeebies videos are an effective tool for enhancing vocabulary acquisition, providing engaging and meaningful learning experiences for students.