The fundamental factor of environmental education is teachers who are well-informed about environmental issues. This research aimed to determine prospective Turkish elementary science teachers' knowledge level about causes, consequences and reducing of the greenhouse effect and to investigate the effect of gender, information source and membership in the environmental foundations on their knowledge. We also aimed to learn their views on environmental education given in university. Twenty-six Likert-scale items developed by Cin (2006) were used for data collection. The scale was applied to 215 prospective teachers from two universities in eastern Turkey. Results indicated that the majority of prospective teachers had misunderstandings about causes, consequences and reducing of the greenhouse effect. According to the analysis of demographic variables, there were significant differences in participants' mean scores based on gender and information sources. Additionally, prospective teachers found environmental education inadequate for different reasons.