This paper presents findings from a case study intended to develop understanding of the practices within education for sustainable development at a preschool in Sweden and highlights its work with two themes: The Health of People and the Planet and Human and Animal Societies. This case study was part of a large school development project conducted by a university in collaboration with a municipality between 2017 and 2019. The preschool had two units with a total of 36 children aged 1–6 years, and 8 preschool teachers. Empirical materials were collected from observations of educational activities at two events, as well as group discussions with teachers and the preschool head teacher. Findings show that the interconnectedness of, and interdependencies between, the environmental, social, and, to some extent, economic aspects of sustainable development were present in educational practices of the preschool. They also indicate that young children, with support and encouragement from their teachers, can take responsibility for activities that are meaningful to them. In this preschool, children’s opinions were respected, and they were given the opportunity to participate in decision-making activities of relevance to their lives.