This study examined the effectiveness of persuasive writing instruction using the Self-Regulated Strategy Development (SRSD) model with high school students identified with attention deficit/hyperactivity disorder (ADHD). Using a multiple baseline design across participants, four students in grades 10 and 11 received one-to-one instruction in planning and persuasive essay writing. Instruction had a pronounced positive effect on students' writing. Essays were longer, more complete, and of higher holistic quality. Additional increases were seen in planning time, writing time, and the number of transitional words and phrases. These results suggest that instruction following the SRSD model is effective for use with high school students with ADHD and contributes to the growing body of literature addressing strategy instruction in writing at the high school level. (Contains 3 figures.)