This study investigated the effects of two approaches to teaching writing (product and process) on the development of writing skills of Moroccan EFL high-school students. Two intact classes of 86 third-year high-school students participated in the present study. A pre-test was administered to all participants to measure their writing competence in expository essay writing. Each group was then subjected to a specific treatment. The experimental group was instructed to use a process-based syllabus, while the control group followed the original product-based syllabus. In the process-oriented syllabus, students were guided through various stages of the writing process via activities like brainstorming, collaborative problem-solving, free writing, multiple drafting, structured peer feedback, and teacher-student conferences. Conversely, the product-oriented syllabus focused on teaching writing through model analysis, writing exercises, and structured feedback sessions with teachers. Following the instructional period, participants underwent a post-test to assess the impact of each approach on their writing proficiency. Statistical analyses, including Paired Samples T-test and Independent Samples T-test, demonstrated that both approaches led to improvements in students' writing performance, with the process-based approach being more effective. Participant feedback on the questionnaire also supported these findings. The study concludes by outlining implications for the teaching of writing in second language (L2) contexts.<p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/lit/0757/a.php" alt="Hit counter" /></p>