This single-subject study examined the functional relation between using a web-based graphic organizer (WBGO) with embedded self-regulated learning (SRL) strategies and additional brainstorming supports on the planning and persuasive paragraph writing of three, secondary students with Complex Intellectual Profiles (CIPs). A multiple-probe design was used to demonstrate a functional relation between the dependent measures and the intervention across baseline, WBGO use, and maintenance phases. Dependent measures included total number of written words, number of sentences, number of transition words, and holistic quality of writing produced. Five explicit lessons in persuasive writing and the use of the WBGO were completed. 1:1 with the primary researcher prior to WBGO use and an additional small group lesson (3:1) was completed prior to entering the maintenance phase. Visual analysis of the data and calculations of effect sizes using multiple overlap methods including PND, PEM, and PAND, indicated that all three students improved their persuasive paragraph writing due to the intervention. Overall, students wrote more words, sentences, and transition words, and scored higher in holistic writing quality from baseline to WBGO use. Students maintained an overall higher mean level in maintenance compared to baseline across all measures. Social validity was also assessed through semi-structured student interviews. Analysis of post-intervention interviews suggests that the intervention was socially valid as most students expressed that their perceptions of the lessons, strategies, and the WBGO were positive. Implications, limitations and directions for future research are discussed.