The present study aimed at developing some EFL vocabulary learning among prospective teachers of English through using working memory strategy. The participants of the study consisted of fourth year English section students enrolled in Faculty of Education, Benha University (N=40) during the first semester of the academic year 2020/ 2021. The study followed the one-group pre-post test design. Four main tools used were: An EFL vocabulary learning checklist required for fourth year students, an EFL pre vocabulary learning test to measure some of students' vocabulary learning skills, an EFL post vocabulary learning test to measure some of students' vocabulary learning skills, an EFL vocabulary learning skills rubric to score students' performance on the EFL vocabulary learning skills tests. In addition, the study used quantitative method for collecting and analyzing the data. t-test was used to compare the mean scores of pre and post test of the study participants. Working Memory Strategy was applied on the participants during the first semester of the academic year 2020/2021. Results of the quantitative analysis revealed that the participants' EFL vocabulary learning skills were improved significantly as a result of using Working Memory Strategy. Therefore, it can be concluded that using Working Memory Strategy is effective in improving EFL prospective teachers' vocabulary learning.