This thesis means to find out how preschool teachers are working to demonstrate the importance of recycling and reuse for children. My hope is to contribute knowledge about various practical methods to establish the idea of sustainable development in the operation. I have used the method of qualitative research and done semi-structured interviews with preschool teachers on certified green flag preschools. The questions I have asked for example concerned how the preschool teachers have worked with recycling and reuse, how much the children have been able to influence and if other didactic subjects are implicated. Six interviews were made and these are summarized in the result part. The analysis shows that all teachers want to teach the children the importance of protecting our earth and what actions each person can contribute with. Even in my search through earlier literature, this has been emphasized since the children absorb a lot of knowledge during the preschool age. Reuse and recycling is integrated into the operation and are not something that is done out of the ordinary. The preschool teachers did not consider it to be any difficulties or obstacles. It rather simplified their work because the policy document gets integrated.