The aim of this study is to investigate the effect of using WhatsApp on developing fifth grade EFL students’ speaking skill during the first semester of the academic year 2020-2021. To achieve this purpose, the researchers selected carefully a representative sample of 46 male students studying at Jijin Secondary School for Boys. The participants were already divided into two groups; a control group of 21 students and an experimental one of 25 students.This study tended to apply this experiment by using the quasi-experimental method. The instrument was a performance test in a shape of an interview that was used as a pre-test and a post-test. Moreover, this test was used to measure any possible differences between the both groups. The results of the study indicated that there were statistically significant differences between both of the groups and the mean scores, in favor of the experimental one in speaking due to the suggested strategy of using WhatsApp.In the light of the findings, the researchers recommend the necessity of implementing contemporary strategies such as WhatsApp in teaching and learning English speaking skill. Besides, the researchers suggest that further studies should be conducted on the effect of WhatsApp on developing other English language skills and in other language competences.