Principals have an important role to play when it comes to making decisions on organizational reforms and priorities in preschool; however, there has been little focus on their views on education for sustainable development (ESD) at the preschool level, which is a reform that needs to be prioritized. Furthermore, there is little insight into similarities and differences when it comes to how different types of preschools incorporate ESD, especially from the point of view of management. For this reason, this study aims to find out about the views on ESD that principals of eco-certified and non-eco-certified preschools have. A further aim is to examine whether there are any differences between the two types of preschools – eco-certified and non-eco-certified – as made evident in the principals’ descriptions of ESD. This qualitative study applies a cross-sectional design. Seven principals, who headed a total of 22 preschools located in six municipalities in Sweden were interviewed: these interviews were audio-recorded and transcribed, and a thematic analysis was conducted. The findings demonstrate that the principals consider ESD to be crucial in early childhood education and feel ESD needs to be integrated into preschool education. Going by the principals’ descriptions, it seems that the eco-certified preschools prioritize ESD in their daily educational practices more than non-eco-certified preschools do. Further studies are needed to explore the attitudes and actions of principals when it comes to heading ESD in preschool, since attitudes guide both actions and behavior.