While preschool educators are currently encouraged to educate young children in and for sustainable development, limited observational research has focused on documenting how sustainability notions are introduced or discussed in preschools. Drawing on a large database of videos of practice, this study describes typical features of conversations about sustainability in Singapore Kindergarten 1 classrooms (4–5 years). Four representative conversations (two planned, two incidental) are qualitatively analyzed to illustrate the strengths and weaknesses of preschool educators’ pedagogical moves. The analyses indicate that while educators build upon children’s experiences and provide real-life examples, their interactional styles tend to be direct, prescriptive, and somewhat rigid. The study, therefore, raises awareness among early childhood practitioners about the need for more dialogic forms of interaction. Children need increased opportunities to have a voice in conversations about sustainability issues. Facilitating deeper discussions will require preschool educators to position themselves as co-constructors of knowledge, attitudes, and behaviors for a more sustainable future, rather than as mere transmitters of information.