In my graduate thesis „Environmental awareness of younger school-age students“ I wanted to check how younger school-age students behave towards environment. Main goals of this thesis were to teach students about the types of environmental contamination, to awake responsible behaviour of students toward environment and to check environmental awareness of younger school-age students. In the theoretical part of my graduate thesis you can find definition of ecology, environmental awareness, environment and the sustainable development, also, you can find information about division of ecology and it's connection with environmental protection as well as the protection of nature. Here are described different environmental contamination and the analysis of the tasks of environmental education in curriculum in the Republic of Croatia. In the empirical part of the thesis the results of the research conducted in elementary school „Ivana Brlić-Mažuranić“ in Slavonski Brod were presented. I questioned the students about their behaviour and behaviour of their families in the situations that are connected with the environmental awareness. The results showed that most of the students properly behave in the given situations although there is some space to work on their environmental awareness. I wanted to influence responsible behaviour of students toward environment with the prepared activities and to introduce them with the environmental problems that we see every day. In my opinion, I achieved the goals of my graduate thesis and I think that the surveyed students have a great deal of environmental awareness that should be more encourage and develop through various activities and changes in educational system.