This study examines the effects of an English vocabulary video on second language vocabulary learning by English as a foreign language (EFL) learners. The conceptual framework is underpinned by Mayer's (2005) Cognitive Theory of Multimedia Learning. The participants were 25 undergraduate students studying at a Thai university. To collect data, five types of research instruments were utilized including a survey of English vocabulary knowledge, pre-test, post-test, the English vocabulary video, and a questionnaire. The findings of this study revealed an increase in the post-test scores after the Thai EFL learners engaged in learning second language (L2) vocabulary using an English vocabulary video. Moreover, the findings also uncovered that the EFL learners gained L2 vocabulary knowledge after viewing the video containing first language (L1) and L2 captions, images, and L2 audios which are relevant to the target words. Furthermore, the results revealed that the EFL students preferred learning L2 vocabulary via video containing both L1 and L2 captions, interesting and related images, and the proper volume of audios. Therefore, the significant findings of this study lead to theoretical and pedagogical implications regarding the significant role of multimedia learning in terms of the links between visual and auditory information.