This study aims to determine the self-efficacy beliefs and attitudes of pre-school teacher candidates towards environmental education and to examine the relationship between these two variables. The research was conducted based on an exploratory sequential mixed-methods design. The participants of the study are 114 pre-school teacher candidates studying at a state university in the central Anatolia region during the 2019-2020 academic year. In the study, quantitative data was collected using the attitude scale towards environmental issues, and a self-efficacy scale for environmental education, while qualitative data was collected through semi-structured interviews with 35 teacher candidates. Quantitative data were analyzed in the SPSS program using statistical analyses suitable for research problems. Qualitative data were subjected to content analysis. As a result, it was found that the self-efficacy beliefs and attitudes of pre-school teacher candidates in environmental education were moderate. While these factors do not show a significant difference by gender, they show a significant difference compared to the variables of self-efficacy in taking previous courses related to environmental education and giving a course related to environmental education in the future. In addition, it has been found that there is a positive relationship between self-efficacy beliefs in environmental education and in attitudes towards environmental issues. The results obtained in the interviews are consistent with these results. As a result of the research, recommendations were made such as providing courses related to environmental education at all levels of education; and providing opportunities for pre-school teacher candidates to practice environmental education in the process of their university education.