In this article, we describe a case study research conducted to validate a set of lesson plans specifically designed for collaborative work with children. A group of nine teachers implemented the lessons in their classes. Data were gathered by means of ethnographical notes to determine children's reactions to collaborative work. Class observations and surveys to teachers on their perception of the lesson plans and collaborative learning were used to collect the data. Results show that children can indeed work in collaboration when given the adequate conditions. This kind of work among children helps them to negotiate meanings and find solutions for learning spaces. Implications point in the direction of teacher education programs that can help teachers understand the principles and practices of collaborative learning with children.