Research shows that the most important skill to possess when learning a previously unknown word is to be able to interpret its meaning based on the context in which it is found (Nation, 2001). This is especially true for L1 learners, but regrettably, research shows, not as true for students learning a second language (Nation, 2001). The aim of the present study is therefore to investigate what differences, if any, there are between advanced learners' inferencing skills in their first versus their second language. This is done by subjecting 15 first-term university students to two parallel inferencing tests in their L1 (Swedish) and L2 (English) respectively. Although the number of inferences and the success rate vary from student to student, the results of the present study show that the learners made extensive use of contextual clues, in their L1 as well as in their L2. Also, the success rate was comparatively high, indicating the great potential learners possess for inferencing. However, in order to improve the students' results, it may be that the teaching syllabus needs to make room for instruction on how to make use of contextual clues so that the potential learners clearly possess is nurtured further.