This quasi-experimental study investigates the effect of Collaborative Writing (CW) on the writing performance and their perceptions of 36 Grade 9 female students in Oman. The study, rooted in the shortcomings of traditional product-oriented writing instruction, employs pre-/post-writing tests and a questionnaire to measure the effectiveness of CW. The findings reveal a statistically significant improvement in the experimental group's writing scores, emphasizing the positive influence of CW on various writing components. Additionally, students express favorable attitudes towards CW, particularly in editing and revising texts collaboratively. Despite these positive outcomes, challenges such as unequal work distribution within groups are identified. The study concludes by acknowledging limitations and suggesting avenues for future research, emphasizing the potential of CW to enhance students' writing skills and foster constructive dialogue in language classrooms.