This study aims to reveal the effectiveness of documentary-based augmented reality applications in environmental education compared to the direct instruction method supported by the question and answer technique. The research was designed as mixed-method research, and the study group consisted of 118 tenth grade students. T-tests were used to analyse the quantitative data, and descriptive analyses were used to analyse the qualitative data. In the study, it was found that the first source of information for students about environmental problems is school. The quantitative results of the study showed that documentary-based augmented reality applications in environmental education are more effective in relating learned information to daily life. Qualitative results of the study also revealed that this education is more effective in enabling people to contemplate the behavioural consequences of environmental problems. Moreover, it was observed that the students who received this education explored more reasons in their statements about environmental problems.