This paper examined the effect of mobile learning (M-learning) on English vocabulary recall with the screen size serving as the moderating role. In this regard, a multi-group quasi-experimental scheme was adopted as pretest-posttest. The population consisted of all students (8 to 14 years old) participating at elementary levels I and II at Language Institute of Mashhad Department of Education, District 4. A total of 112 students were selected from the Institute and were then randomly divided into two groups using mobile devices (small screen) and computers (large screen). Then, the subjects in each group were randomly divided into four subgroups. All subjects participated in a vocabulary recall quiz before and after the treatment. The findings suggested a significant difference between the groups in terms of vocabulary recall. The textual/visual and textual presentation groups significantly outperformed the control group, whereas no significant difference was seen in the visual group. The participants receiving the instructions on a large screen performed better in the vocabulary recall quiz, while the effects of screen interaction and presentation type on vocabulary recall were insignificant. The learner’s performance is enhanced in multimedia education by providing educational materials both in verbal and non-verbal channels. Providing educational materials through small screens may lead to attention and perception difficulties.