In the realization of an effective environmental education, the opinions of secondary school students about environmental problems are considered important. Therefore, the general purpose of the research is to determine the opinions of secondary school students about environmental problems by using the cartoons drawn by the students. The study group of the research consists of 28 students studying in primary education second grade in the 2020-2021 academic year. The research is a case study conducted with a qualitative research approach. The findings of the research were analyzed by content analysis. According to the results of the research, the students stated that the most important environmental problem was pollution. Students stated that environmental pollution, air pollution, garbage problem, wastes, water pollution, deforestation, depletion of natural resources were the first among environmental problems. According to the other finding of the study, the students mostly mentioned the individual responsibilities that people should fulfill in solving environmental problems. Based on the results of the research, a lesson that can be taught at all levels starting from secondary school be created under the name of environmental education, in which applied activities will be mainly included.