The aim with this qualitative study is to contribute with knowledge on how the participation of young children is expressed and enabled or prevented in the library room. The result of the study was gathered using the method participant observation which took place at two different occausions in a library where the participants were four librarians, nine caregivers and 11 young children at the age 0–3 years old. The result of the participant observation was then analyzied and categorized through five themes with focus on young children's participation. The analytic framework made it possible to see those five themes. The result of the study showed that young children´s participation was expressed when they used their bodies and senses as they interact with others and the environment of the library room. The librarians had designed the room with some easily acessible furnitures that enabled participation. While other furnitures prevented participation because they created tight spaces where the young children could not move their bodies freely without hurting themselves or others. Some parents enabled participation when they supported the young children’s different ways of expressing participation. While other parents prevented participation when they supervised that the young children instead used the library room as a calm and silent place were they sat down and read books together with the parents. My conclusion is that the librarians have to design the environment of the library room so it attracts both the young children and their parents to express participation together by not only using their voices freely but also their bodies and senses when they interact.