This study examines the effects of working memory capacity and content familiarity on literal and inferential comprehension in second language (L2) reading. Participants were 62 Turkish university students with an advanced English proficiency level. Working memory capacity was measured through a computerized version of a reading span test, whereas content familiarity was achieved through "nativization" of a narrative, that is, textual and contextual modification to reflect the reader's own culture. After completing the reading span test, the participants were randomly divided into two groups, one being exposed to the original text and the other to the nativized version. They then answered multiple-choice comprehension questions aiming to check literal and inferential comprehension. The results revealed independent and additive effects of working memory capacity and content familiarity on inferential comprehension. No effects were observed on literal understanding. These findings have implications for the design of assessment instruments in L2 reading comprehension. (Contains 1 figure, 3 tables and 4 footnotes.)