The assessment of children's behavior within the context of preschool education is closely linked to making important decisions regarding their development, upbringing, and education. Through assessment, educators support their decisions on the methods of upbringing they will implement in their classroom and/or their choice to seek additional help from specialist counselors to effectively address children's behavior problems. This book examines the assessment of preschool children's behavior and presents the design and standardization of the revised Preschool Behavior Checklist (PBC-R). The purpose of the PBC-R is to gather information about children's daily behavior in the classroom from their educator. Specifically, the book describes the types of behavior problems assessed by the PBC-R, the administration and scoring of the checklist, as well as its psychometric properties, which substantiate the validity and reliability of its results. The aim of the book is to serve as a useful addition to the "arsenal" of preschool educators who daily encounter various behavior problems in the classroom and are called upon to assess or address them. Additionally, the book will be useful to students studying issues of development, upbringing, and education of young children, as well as to special educators, psychoeducators, and school psychologists who are called upon to diagnose and subsequently design and implement early intervention programs to effectively address preschool children's behavior problems.