This study aimed to analyze the implementation of the collaborative writing strategy in teaching procedure texts at the eleventh grade of Madrasah Tarbiyah Islamiyah Pasia Agam. The research was conducted using a qualitative case study design to obtain an in-depth understanding of the teaching and learning process. The participants consisted of an English teacher and eleventh-grade students who were involved in collaborative writing activities. Data were collected through classroom observations, interviews, and document analysis. The findings revealed that the implementation of collaborative writing encouraged students to actively participate in brainstorming, discussing ideas, organizing procedural steps, and revising texts collaboratively. The strategy helped students improve their understanding of the generic structure and language features of procedure texts while enhancing their confidence, motivation, and engagement during writing activities. Furthermore, the collaboratively produced texts demonstrated better organization, clearer procedural steps, and more appropriate language use. However, several challenges were identified, including unequal participation among group members, differences in language proficiency, and difficulties in reaching consensus during group discussions. Despite these challenges, collaborative writing proved to be an effective instructional strategy for improving students’ writing skills and promoting cooperative learning. Therefore, teachers are encouraged to provide clear guidance, assign balanced responsibilities, and monitor group interactions to maximize the effectiveness of collaborative writing activities.