The present study replicates and extends previous research regarding the effects of self-regulated strategy development (SRSD) within a school wide positive behavior support model among students with writing difficulties who also had either internalizing or externalizing behavior patterns. Two multiple-probe designs, involving 13 second-grade students, are reported. Students with internalizing behaviors (5 girls, 1 boy) and those with externalizing behaviors (1 girl and 6 boys) learned how to plan and write persuasive essays using the SRSD model of instruction. Lasting increases in persuasive essay elements as well as improvements in length and quality of writing were found across both groups of students. Both rating scales and interviews indicated high social validity among classroom teachers and students. Limitations and directions for future research are presented. (Contains 5 tables and 2 figures.)