The main aim of this study was to determine the factors that affect the environmental literacy (EL) of 15-year-old students in Germany. The data were based on findings from the PISA 2015 of German students (n = 6.504), which were published on the official PISA site (http://www.pisa.oecd.org). According to the results, there was a positive and meaningful relationship between EL and environmental optimism (EO) at a low level. There was a meaningful relationship between EL and socioeconomic characteristics (SEC). Moreover, SEC has a large effect on the EL. There was a significant relationship between both classic literature and books on art, music, or design that students have at home, number of musical instruments at home, and EL. There was, however, no significant relationship between both 'books of poetry' and 'books to help with school work that students have at home' and EL . Results show that there was a significant relationship between some of the selected teaching characteristics (frequency of adapting lessons, teachers' providing individual help, teachers' explanations of scientific ideas, and teacher changing the structure) and EL, while there was no significant relationship between EL and teachers continuing frequency of teaching. Recommendations for the promotion of EL in schools are discussed.