With the advancement of technology and its role in making life more convenient, some EFL teachers prefer to use it in their classrooms. In view of this, the current study aimed to explore the effect of Anki and WhatsApp on the vocabulary retention of Iranian EFL learners. The study’s design was quasi-experimental with three groups of WhatsApp-based vocabulary instruction, Anki-based vocabulary instruction and the traditional one. Sixty EFL learners studying English in a language institute participated in the study, and were divided into three groups of twenty. To ensure their homogeneity, a Solution Placement Test was given to them. After the treatment, the post-test was given to them to check their vocabulary retention. The results of the repeated measures ANOVA indicated that Anki-based and WhatsApp-based vocabulary instruction were effective in enhancing their vocabulary retention. The results of MANOVA showed that there were significant differences among the three groups in their vocabulary retention.
