Computer Assisted Language Learning (CALL) integration in EFL contexts has intensified noticeably in recent years. This integration might be in different ways and for different purposes such as vocabulary acquisition, grammar learning, phonology, writing skills, etc. More explicitly, this study is an attempt to explore the effect of using CALL on vocabulary acquisition of EFL learners. It also discusses CALL applications for vocabulary instruction and searches for efficient methods to integrate CALL in vocabulary acquisition. For the discussion, it reviews the results of previous international and Iranian studies on CALL integration in vocabulary instruction to illustrate the state of research in this field. Based on the literature review, it is proposed that further research is required to find out the influences of CALL on different facets of vocabulary knowledge. At the end, some pedagogical implications have been offered for EFL teachers and learners.