Using the self-paced reading paradigm, the present study examines whether highly proficient second language (L2) speakers of German (English first language) use case-marking information during the on-line comprehension of unambiguous "wh"-extractions, even when task demands do not draw explicit attention to this morphosyntactic feature in German. Results support previous findings, in that both the native and the L2 German speakers exhibited an immediate subject preference in the matrix clause, suggesting they were sensitive to case-marking information. However, only among the native speakers did this subject preference carry over to reading times in the complement clause. The results from the present study are discussed in light of current debates regarding the ability of L2 speakers to attain nativelike processing strategies in their L2.