The present study explores the environmental attitudes (EA) of senior high school students in Turkey, explains which determinant factors affect these EAs, and concludes with some suggestions for curricular reform. This study includes over nine hundred students from different school types, neighbourhoods, geographical regions, and socioeconomic backgrounds. The researcher used two different questionnaires that were based on postmaterialist values: one based on the New Environmental Paradigm (NEP) and the other developed by the researcher called the General Environmental Attitudes and Perceptions (GAP). The results of ANOVA and t-tests show that EAs of students vary depending on school type, gender, parents' education levels, parents' political views, professions, and household income. Students at public high schools, females, lower middle class students, students with well educated parents in white-collar professions, and students with liberal parents have more pro-environmental attitudes than the others. Students from vocational schools, almost all of which are based on single-sex education, have scored the lowest on both surveys.