Although the use of course management systems has increased significantly in educational settings, these new user-friendly systems have not been widely employed by second language (L2) institutions and practitioners. As an attempt to shed more light on the effectiveness of Moodle as one of the most popular course management systems for educational purposes, the purpose of the current study was to examine the impact of a Moodle-supported language course on the grammar performance of Iranian English as a Foreign Language (EFL) learners. To accomplish this objective, a number of 46 Iranian EFL learners who were the students of two intact classes took part in the research as the participants. One of the classes (n=25) was randomly assigned to the experimental group, and the other class (n=21) was considered as the control group of the experiment. The students of the experimental group were instructed in a blended learning mode in which Moodle was supplemented to face-to-face, traditional teaching, while the students of the control group were instructed traditionally without the aid of Moodle. To measure the dependent variable of the study, a grammar test constructed by the researchers was given to the students as the pre-test and post-test of the experiment. The results of data analysis indicated that the Moodle group students outperformed the traditional group students in terms of grammar performance, suggesting that CMS-supported grammar instruction via Moodle contributed to improving the EFL students’ grammar performance. The discussion and the implications of the study were finally presented.
