vocabulary as a major component of language learning has been the object of numerous studies each of which has its own contribution to the field. finding the best way of learning the words deeply and extensively is the common objective of most of those studies. however, one effective way for achieving this goal is somehow neglected in the field. using a variety of activities such as games can reinforce the teaching points without boring the students. the present study is aimed at investigating the immediate and delayed effect of language games on pre-intermediate students’ vocabulary learning. 28 number of students were chosen. as institute students; they were at the same level of proficiency and were divided into two groups of 14. the control group received traditional method of teaching vocabulary such as: drills, modals, definitions, etc. and the experimental group was exposed to language games as a treatment. the treatment of the study took 4 sessions of 30 minutes. before starting the treatment, a 40-item vocabulary test was prepared to recognize the unknown words to the students and select them as the basis of the treatment. then the treatment started. at the last session of the treatment an immediate posttest was administered to check how much students have improved. two weeks later another test (delayed posttest) administered to check the participants’ retention after a period of time. after administering the two tests, the results revealed a statistically significant difference between the means of the 2 groups in the both immediate and delayed posttests which implied that the application of language games can reinforce the subjects’ vocabulary learning. key words: language games, cooperative learning, retention, motivation, vocabulary