The purpose of this study is to investigate pre-service science teachers' sustainable environmental education behaviour and the factors affecting them in terms of some variables (gender and grade level). The study group of the current research is comprised of 206 pre-service teachers attending the Department of Science Education in the Faculty of Education of Kirsehir Ahi Evran University. The study employed the descriptive survey method, one of the quantitative research methods. As the data collection tool, "The Sustainable Environmental Education Behavior Scale" developed by Demirci Güler and Afacan (2012) was used in the study. The calculated Cronbach alpha value of the scale was found to be [alpha]=0.90. In the statistical analysis of the data, SPSS was used. In the analysis of the data, Independent Samples t-Test and One Way ANOVA were run. It was found that the pre-service science teachers' scores of behavior towards sustainable environmental education do not vary significantly by gender. In addition, a significant difference was found between the 2nd and 3rd grade pre-service science teachers' average scores in favor of 2nd grade in the Environment-Friendly and Recyclable Products sub-factor of the scale.