Looking throughout history, the improvement of technology and science has changed the way people live. Although it improved the quality of human life, it resulted in many problems in nature. With an insight into the already created consequences caused by the destruction of nature, there is an increase in interest in environmental protection and sustainable development. In order to achieve both, it is necessary to develop environmental awareness, which is considered a prerequisite for solving the present environmental problems. Ecological upbringing and education, which are in the Republic of Croatia, implemented during preschool, elementary and high school education, play a significant role in the development of environmental awareness. In addition to the above, there are programs that can be implemented in schools, which place special emphasis on the importance of environmental education. An example of such a program is the international Eco-school program, which aims to implement environmental education in all parts of the educational system and in the daily life of all participants. As the development of ecological awareness is a neccesity in ecological action, the aim of this paper is to examine the ecological awareness of 8th-grade eco-school students. Through this research in this paper, we try to get an insight into the knowledge, attitudes and habits about the environment that students of eco-schools have and practice. The research was conducted using an online survey, and the sample consisted of 124 male and female students of the 8th grade of schools in the area of the City of Zagreb, where it was necessary that the school had an active eco-school status. The analysis of the research results showed that the students of eco-schools mostly show a high level of knowledge, positive attitudes and pro-environmental behavior, but also that there is room for improvement in all areas.