Inspired from problematic nature of writing, this study adopted an action research through peer editing as a way of developing writing skills of students at an ELT department. This study was designed through the specific stages of an action research which are planning, action, observation and reflection. In planning and action stages, the researchers designed general and specific criteria to follow during the cycles, and they applied these criteria accordingly. In observation stage, the peer editing processes in specific cycles were observed. The researchers used cycles at this stage. These cycles were application processes which were followed step by step during peer editing. In reflection stage, reflections of the participants on peer editing in writing classes were gathered through a form. Qualitative data collected from participants were analyzed and reported descriptively at the end. The reflections were categorized as before and after writing classes, advantages and disadvantages of peer editing. In conclusion, peer editing in writing classes affects foreign language learners positively, and peer editing can be used in writing classes as an alternative way of developing ELT students' writing skills. [This paper was presented at the "GlobELT 2019 Conference: 5th International Conference on Teaching and Learning English as an Additional Language" (11-14 April 2019, Merit Park Hotel, Kyrenia-Northern Cyprus).]