The present study aims to evaluate the effects of an argumentative writing strategy (POW+TREE) on four struggling ninth graders' ability to produce persuasive texts regarding their point of view on different questions. I applied a multiple-baseline design to evaluate outcomes across participants. The results indicate the intervention helped students to write more extensive essays, and evidence shows an increase in quality. Follow-up data suggest the effects remained after the treatment ended. I also discuss future research and the findings' implications for practitioners.