<p>The capacity to rapidly and accurately recognize a word's phonological form and connect it to knowledge of the word's meaning is essential for listening comprehension. Without adequate levels of lexical knowledge, the listener must depend on compensatory strategies such as guessing from the context, which is significantly more difficult than when reading, and may result in comprehension breakdown. It is therefore important for teachers and researchers to more fully understand the relationship between lexical knowledge and L2 listening development. Critical to this understanding is an appreciation of the modality-specific nature of the lexical knowledge that most strongly underpins successful listening comprehension, the so-called aural lexical knowledge. Developing a better understanding of the relationship between aural lexical knowledge and L2 listening will be important in future efforts to promote second language acquisition among language learners. This chapter begins by defining relevant key concepts related to aural lexical knowledge. It then goes on to elaborate upon the relationship between aural lexical knowledge and L2 listening, including an overview of the empirical research demonstrating the centrality of aural lexical knowledge to L2 listening comprehension. Next, alternative approaches to the development of aural lexical knowledge are presented. Finally, recommendations are made for future research that may contribute to a more refined understanding of the relationship between listening and lexical knowledge.</p>