Various environmental problems are related with wrong risk perception about the environment as well as insufficient interest, behavior, information and environmental perception. The purpose of this study was to investigate the risk perceptions of secondary school students. The participants were 320 secondary school students aged between 15 and 17. Environmental Risk Perception Scale developed by Slimak and Dietz (2006) was used in the study. The validity and reliability analysis of the scale was completed. The result of the exploratory factor analysis showed that the scale consists of 4 factors explaining the 57% of the total variance. The internal consistency coefficient Cronbach-alpha of the scale was 0.89. The reliability coefficient Spearman-Brown calculated by split-halves test method was found to be 0.74. The environmental risk perception which was found to be above average show that awareness of the students about environmental problems is high. According to students the three most important environmental risk factors are respectively, greenhouse effect which is among global environmental risks, radiation which is among the chemical environmental risks and ozone layer thinning which is again among the global environmental risks. According to this ranking, it can be concluded that students have a different risk perception than experts.