Students with attention deficit hyperactivity disorder (ADHD) often experience serious academic deficits. One area that is particularly problematic is written expression. This study assesses the effectiveness of a persuasive essay-writing strategy taught by using the self-regulated strategy development model on the writing skills of 3 high school students with ADHD. Results indicate a marked improvement in the number of essay elements, length, and holistic quality of students' essays. Planning time also increased. The students maintained gains at 3-week follow-up. The article also discusses implications for future research and practice. (Contains 5 figures.)