The purpose of the study was to reveal the effects of scientific argumentation-oriented teaching activities on the environmental attitudes and knowledge of seventh-grade Turkish students within the human and environment unit compared to the activities suggested by the ministry of education science and technology curriculum. This study employed a "Quasi-experimental design with pre-test-post-test control group" quantitative research design. A total of 57 seventh-grade students participated in the study, 29 in the test group and 28 in the control group. The research was carried out in a public school in the Melikgazi district of the Kayseri Province in the 2012-2013 academic years, where the study's was conducted over a total of 16 h. Research data were collected through a 24-item environmental knowledge test and a 20-item environmental attitude scale after granting permission of the researcher who was working on environmental education. Independent samples t-test analyzes were performed for the dependent variable environmental knowledge level. As the scores of the participants were not normally distributed in the environmental attitude scale, the analysis of the scores obtained from this scale was performed by nonparametric Mann-Whitney U-test. As a result of the analysis, it was observed that the participating students' environmental knowledge post-test scores significantly differentiated in favor of the test group (t (55) = 2.564, ? = 0.013). Environmental knowledge post-test results revealed that scientific argumentation-oriented teaching activities were significantly more effective on students' environmental knowledge compared to the control group. However, no significant difference was found between the environmental attitude post-test scores (U = 311.5, ? = 0.129). Therefore, it was concluded that teaching activities focused on scientific argumentations had no effect on these students' attitudes toward the environment. Regarding the results of the study, the effect of this method on students' environmental attitudes should be compared at secondary school, high school, and university levels.