Vocabulary learning has always been a major concern for second language learners. Particularly for those who are just beginning to learn English. Usually a long list of vocabulary items is given to learners and they have to memorize all of them. The present study using a quasi-experimental design aimed to determine whether teaching vocabulary through instructional games can affect the vocabulary enhancement of students. The participants were 40 pre-intermediate EFL students who were equally divided into two groups. To this end, the two groups of students were assigned as control and experimental groups. The control group was exposed to textbook teaching and the experimental group was exposed to instructional games. After analyzing the obtained data, no significant differences were found... between the two groups on posttest, as both programs made progress in the subjects. However, after two weeks, a delayed post-test was conducted to see the retention of learners' knowledge of vocabulary. In the end, although both groups had changed positively, a significant change was seen in the retention of learners' knowledge of vocabulary in the experimental group.