Reading-while-listening (RWL) has been suggested to facilitate reading comprehension by establishing letter-to-sound correspondences in the word recognition process. However, previous findings are inconsistent regarding the effect of RWL on foreign language (L2) reading comprehension. To understand why such inconsistency occurs, the moderating role of L2 orthographic characteristics in the effects of RWL on L2 propositional comprehension was examined. The orthographic characteristics of a language are of particular relevance as languages differ in the time course and the degree to which visual and phonological coding strategies are involved in word recognition. L1 Korean (alphabetic, shallow orthography) intermediate undergraduate learners of Chinese (nonalphabetic), English (alphabetic, deep orthography), and Spanish (alphabetic, shallow orthography) read and read-while-listened to authentic reading texts in their target language, and solved a set of written, untimed multiple-choice questions to test their propositional comprehension. Results indicated that learners of an L2 with a larger distance (i.e., Chinese) from the L1 benefitted more from RWL, indicating that L2 orthographic characteristics interacted with input modality. Pedagogical implications for the use of RWL are discussed coupled with qualitative findings of students' perceptions.