This Swedish quantitative study aims to fill a research gap concerning how preschool teachers understand and work with education for sustainable development. Empirical data were collected in a questionnaire distributed to 187 Swedish preschools. The questionnaires consisted of 13 multiple choice questions and five open ended questions exploring how the preschool teachers interpret education for sustainable development and environmental education both as concepts and in practice. Both education for sustainable development and environmental education were mainly associated with nature experiences, recycling and reuse of resources. Descriptions reflecting the economic and social aspects of sustainable development were mainly missing. These views were reflected in the types of activities the children were afforded. Preschools supported by in-service training had a broader understanding of the concept and worked more actively with environmental and sustainability issues with the children. This suggests the need for support for providing children with quality education about sustainability issues.