Students with emotional and behavioral disorders often experience difficulties in expressive writing and social outcomes in school and beyond. Therefore, writing instruction and self-determination skills are critical for this population. This research study, in which special education teachers were trained to be implementers, successfully intertwined persuasive writing with self-determination instruction to improve students' writing and self-determination skills. Emphasis was given to teaching students how persuasive writing can be used to self-advocate for needs and wants. The Self-Regulated Strategy Development (SRSD) model of writing instruction was examined with a multiple-probe-across-participants design to evaluate the instructional effects. Instruction was provided 4 days per week, 40 min per session, for 14 to 23 days. Visual analyses indicated level changes and a functional relation between the SRSD/self-determination instruction and students' writing skills. Students' essays increased for number of words written, transition words, number of essay parts, and overall quality. Furthermore, students' self-determination perceptions and knowledge as well as writing self-efficacy significantly increased as a result of instruction. Teachers implemented the intervention with high degrees of fidelity. Teacher and student interviews revealed an overall satisfaction with SRSD procedures and results.