Students' ESL writing skills in general are not at a desirable level. The objective of this study was to determine the effectiveness of utilizing the STAD [Student Team Achievement Division] method to enhance descriptive writing skills among students in an international school in Selangor, Malaysia. This study employed an action research design. The sample consisted of 20 Year 6 students aged between 11 and 12 years. The data for the research was obtained using a pre-test and a post-test, focus group interviews with students, teacher's reflection and an observation checklist. The action-research was carried out over a period of 6 weeks. The quantitative data was analyzed using descriptive and inferential statistics and the qualitative data (interviews, teacher's reflections and observations) was analyzed based on emerging themes. The findings from the quantitative data indicated that the STAD method helped to enhance students' descriptive writing skills. The analysis of the qualitative data revealed that students enjoyed writing in groups and they stressed that they learned a lot from their friends when they wrote in groups. The teacher's reflection revealed that the STAD method improved students' writing skills through collaborative learning as they get the opportunity to edit their group essays. Findings from the observation showed that students were actively engaged in the process of writing during group work and their social skills improved too. This study has pertinent theoretical implications, pedagogical implications and practical implications in ESL writing.