Multimedia input can enhance vocabulary learning in the context of learning English as a foreign language (EFL). Drawing upon a mixed method, this study explores the potential of multimedia input in vocabulary learning. EFL vocabulary learning was assessed under four input conditions ("definition + word information + video, definition + word information + audio, definition + word information, and definition-only"). One hundred twenty-five Chinese-speaking university students were randomly allocated to the four conditions. The vocabulary knowledge test focused on receptive and productive vocabulary knowledge and served as a pretest, immediate posttest, and delayed test after 2 weeks. Participants also completed a survey related to their perceptions of the assigned learning mode. Five participants from each input condition completed an individual interview as well. Analyses of covariance supported the pronounced effects of the definition + word information + video condition on vocabulary learning and retention. The questionnaire and interview findings explained the value of multimedia input, particularly in the definition + word information + video condition. Overall, results highlight the importance of audiovisual input in vocabulary learning and retention. Relevant theoretical and pedagogical implications are discussed based on the findings.