This thesis discusses sustainability, environmental protection and the development of ecological awareness of preschool children. The importance of solving environmental issues caused by human activities, especially industrialization, which has led to pollution and ecological imbalance in many ecosystems, is emphasized. The work emphasizes the importance of sustainable development, which includes ecological, economic and sociocultural aspects, and the need for individuals, including children, to play a role in preserving the environment. Furthermore, the paper discusses various methods of raising the environmental awareness of preschool children, covering practical activities such as saving electricity and water, reducing waste, reusing and recycling materials, and promoting outdoor activities in nature. A special emphasis has been given to the roles of educators and parents as role models for children in the development of environmental awareness and the importance of integrating environmental topics into preschool education. The aim of the work was to examine the standpoints of educators and parents in the area of Osijek-Baranja County regarding the application and implementation of environmental protection with preschool children and to determine whether there are differences in their standpoints. The presented results indicate positive standpoints of both groups about environmental protection, and it was also established that both groups support the development of environmental awareness among preschool children. The importance of early childhood education in promoting sustainability and developing environmental awareness in children from an early age is also emphasized.