In vocabulary research, a wide range of test formats have been utilized to measure vocabulary knowledge and learning. However, the majority of studies have assessed vocabulary knowledge through written task formats. Given that there has been increasing attention to the role of spoken input in vocabulary learning (e.g., listening to songs, watching television), we should revisit the construct definition of spoken vocabulary knowledge and discuss how we should measure it. In my talk, I will first discuss the construct of spoken vocabulary knowledge relevant to learners’ ability to communicate in spoken discourse. I will then describe results from my recent studies examining how spoken vocabulary can be measured receptively and productively. To close, I will provide future directions in the field of second language vocabulary acquisition and assessment.