Listening comprehension is a real-time process, yet very little is known about the variables affecting real-time second language (L2) listening. The present study aimed at investigating the effects of syntactic complexity and word frequency on L2 listening. Furthermore, the role of the listener's working memory capacity in listening comprehension was investigated. Fifty-three Dutch learners of French were tested using a working memory task and self-paced listening technique. Working memory scores and reaction times were collected as a measure of processing efficiency. Contrast analyses were run on the reaction times per variable. Correlation tests were run between the working memory scores and reaction times. The results showed that syntactic complexity affects L2 listening comprehension. However, no effect of word frequency on L2 listening and no correlation between working memory capacity and L2 listening in any of the conditions was found. We conclude that linguistic factors shown to affect offline L2 listening are not always generalizable to online L2 listening. We also conclude that working memory considered as a cognitive system separate from other cognitive processes involved in language comprehension does not explain individual differences in real-time L2 listening. Further research needs to be done to better understand (real-time) L2 listening comprehension.