Abstract This study aimed at investigating the effectiveness of using Edmodo as a teaching and learning platform to develop writing skills for third-year prep-stage students for governmental language school. The researcher followed the quasi-experimental approach, so she chose a random sample of 44 EFL students at Bardis governmental language school in the directorate of Sohag. The participants were divided into two groups. The control group of (22) students, the experimental group of (22) students. The two groups were equivalent in terms of their age, previous learning, and achievement in the English language in general, achievement in writing in particular. The researcher used a tool. The tool was a writing test to measure students' writing skills after the administration. The educational platform Edmodo was used as a teaching and learning virtual class for explaining the writing lessons included in the course of the third-year prep-stage. The findings of the study revealed that there was a statistically significant difference between the mean scores achieved by the experimental group and the control group in the post-assessment of student's writing performance in favor of the experimental group. This showed a remarkable improvement in writing skills for the experimental group as compared with the control group.