The main concern of the present study is to examine the effectiveness of using multi-word expressions (MWEs) in developing writing quality of fourth- year English majors at the Faculty of Foreign Languages and Translation, Misr University for Science and Technology .To fulfill the purpose of the study, a total of 54 students were equally divided to represent two groups, 27 for the experimental and 27 for the control groups. A multi-word expressions test consisting of two parts, namely, recognition and production, and a writing quality test were administered as pre-posttests for the two groups before and after the treatment. A 13-session treatment was administered for the experimental group students, while the control group students followed their regular method. Results revealed a clear advantage for the experimental group significantly outperforming the control group both in recognition and production levels. Results also indicated that the experimental group was superior to the control group in writing quality.