Action research is the process of (a) identifying a problem in the classroom, (b) collecting data to better understand the problem, (c) researching evidence-based interventions for addressing the problem, (d) selecting and implementing an intervention, (e) collecting data to determine the effectiveness of the intervention, and (f) making changes to the intervention based on that data. In the special education classroom, action research is an integral part of the IEP process and should be used in IEP planning, implementation, and evaluation. The Teacher’s Guide to Action Research for Special Education in PK-12 Classrooms is intended for use as a textbook in special education action research courses, but includes practical applications and easy-to-understand verbiage for all readers, as well as reproducible data collection forms. The expected readership of the book are current and future preschool through twelfth grade special education teachers. After reading this book, pre-service and in-service teachers will be better prepared for systematically using data to support decision making in their classrooms. Because of the reproducible forms and explicit instructions on the use of action research, readers will be able to immediately begin conducting action research in their own classrooms after reading this book.