This study examines the role of pedagogical documentation on young children's thinking processes. Pedagogical documentation is utilized as part of the Reggio Emilia Approach for several purposes, such as assessment, curriculum planning, and instructional accountability. This study was conducted in a kindergarten classroom that utilizes the Reggio Emilia Approach, at a laboratory school on a college campus. Acting in the role of participant observer I spent nine weeks observing and at times interacting with the students as they engaged in activities involving science kits. I specifically looked at the experiences of the children as they interacted with the pedagogical documentation, either independently or as mediated by the teacher. As the pedagogical documentation was gradually introduced into the setting with increasing use and attention, its impact on the students' thinking processes, including memory, reflection, critical thinking, and metacognition, began to emerge. The results indicated that the pedagogical documentation was most effective in supporting young children's thinking processes when its use was mediated by an adult. Additionally, as the children in the classroom were increasingly exposed to the pedagogical documentation, and as the teacher modeled its use, the children began to use it as a mental tool. These findings offer implications for early childhood educators seeking to implement the Reggio Emilia Approach, and for those seeking to understand more fully the role of pedagogical documentation in developing young children's thinking processes.