This study aims to determine the effect of prediction, observation, explanation supported project based environmental education (POESPBEE) on the attitudes and behaviors levels of eighth grade students compared to teacher-centered environmental education. The study used a quasi-experimental research design including pre-test, post-test and control group. The application step of the study was carried out by the researchers in a ten-week period in 2018-2019 academic year. The study group included 62 students, 34 of whom were in the experimental group and 28 of whom were in the control group. The experimental group was applied the POESPBEE and the control group was applied teacher-centered environmental education. Attitude Scale toward Environment and Behavior Scale toward Environment were administrated as pre-test, post-test and follow-up test to evaluate the attitude and behavior levels of the students in the experimental and control groups toward the environment. Data were analyzed using the Independent Samples t-test and Repeated Measures ANOVA. The study found that the POESPBEE provided a significant development on students' attitude and behavior; however, teacher-centered environmental education could not provide a significant development on the students. Based on this result, it can be claimed that the methods like the POESPBEE, which can change individuals' attitudes and behaviors toward the environment in positive way, should be used in environmental education.