The present study aims to investigate the role of L1 transfer effects on L2 sentence processing strategies during the interpretation of relative clause (RC) attachment ambiguities. The main body of the study is divided into two sections. The first section describes Experiment 1, which is designed to test the resolution of RC attachment ambiguities by Turkish learners of L2 English both in Turkish and English through the use of an off-line task (i.e., paper-and-pencil comprehension tests) and compare their processing preferences to those of native English speakers. The second section presents Experiment 2, which aims to investigate the real-time processing of the RC attachment ambiguities by the same participant groups employing eye-tracking methodology. The results indicated that L1 Turkish and L1 English RC attachment preferences differed and that Turkish learners of L2 English tended to transfer their Turkish sentence processing pattern to real-time interpretation of the English RC attachment ambiguities.