This article reports on a study exploring the respective contributions of first language (L1) listening comprehension ability and second language (L2) proficiency to L2 listening comprehension ability. The participants were 75 Grade 8 English-speaking students learning French. The students completed tests in French and in English that required them to listen to authentic dialogues and to complete a number of multiple choice comprehension questions. Multiple regression analysis indicated that both L1 listening comprehension ability and L2 proficiency contributed significantly to L2 listening comprehension ability, with L2 proficiency having about twice as much common variance. A further analysis by question type indicated that, although the relative contribution of L2 proficiency to the combined variance continued to be higher for both question types, the relative contribution of L1 listening comprehension ability to answering literal questions was greater than for answering inferencing questions. The results are discussed in light of the linguistic threshold and the linguistic interdependence hypotheses and similar research on this same question for L2 reading. This article initiates an exploration of the ability proficiency debate as it relates to L2 listening comprehension ability, discusses implications for L2 pedagogy, and suggests important avenues for further research.