From the beginning of humanity, people should think about environmental protection. But there were always more important things. With its inventions, humanity has disturbed the natural balance without thinking, so at the beginning of this century, ecological problems began to be discussed as they directly affect human health. The concept of sustainable development is conceived so that an individual can successfully meet his own needs without compromising the ability of future generations to satisfy itselve. In order to successfully affect an individual, it is necessary to warn from the earliest age on the importance of environmental conservation. Educational institutions strive to build an ecological conscious person, but it also needs to be nurtured at home. They all testify that nurture comes from home, but what when children spend most of their day in kindergarten? Eco - school program is being developed for the educational institutions in Europe. In order for an institution to become an Eco School, it should be logged on the web site, implement 7 program steps, apply for status and after two years renew the status of Eco School. All educational institutions, including kindergartens, can participate in the program. Although everyone can be in program, this year only 11 kindergartens in the Republic of Croatia have been reported to program. Some kindergartens nurture eco-education, but do not report to the program because they lack the adequate educational staff to expand their knowledge and send them to become an Eco-kindergarten. In the immediate vicinity there are several kindergartens who still receive the Green Flag and the prestigious status of Eco School. These are the kindergarten Sisak Stari - object „Pčelica“ and Kindergarten Osijek - object „Mak“. They have received the Green Flag with their effort and dedication, but have also maintained the status of Eco School for a long time. In the future, more population awareness is expected because adults are working to build a sense of the environment from the earliest age in the present generation. Educators are educated and working on their daily basis to become more quality and improve their work. Including children in ecologically focused activities generates generations that care about the future of the environment they live in. They realize that environment is just where they are at the moment and that they should be kept it as such for the rest, for the offspring. By understanding ecological issues and incorporating into ecological activities, the behavior of children is changing, and through children it affects adults too.