Listening comprehension, which is relatively straightforward for native language (L1) speakers, is often frustrating for second language (L2) learners. Listening comprehension is important to L2 acquisition, but little is known about the variables that influence the development of L2 listening skills. The goal of this study was to determine which learner variables play a significant role in predicting L2 listening success among Grade 4 middle immersion students (N = 84). The variables of interest in this study were L1 and L2 vocabulary knowledge, auditory ability, working memory, and metacognition. Results showed that all the variables, except for metacognition, were significantly related to L2 listening comprehension. Regression analysis revealed that vocabulary knowledge, particularly L2 vocabulary, significantly predicts L2 listening success. The results are discussed in relation to their pedagogical implications for beginner learners of French.