The aim of this study is to investigate the effects of science, technology, mathematics, engineering (STEM) applications and STEM based teaching on 8th grade students' environmental attitudes, scientific creativity, problem solving skills and science achievement and to get students' opinions about STEM practices. Two groups were used in the research, one of which was the control (22 students) and the other was the experimental group (22 students). Experimental design with pretest-posttest control group, one of the quantitative research approaches, was used in the study. In the study, the subjects in the Organisms and Energy Relations unit, which is the 6th unit of the 8th grade science course, were taught to the students in the experimental group in accordance with STEM acquisitions and disciplines and by focusing on STEM practices. The data of the study were collected by using "Environmental Attitude Scale", "Problem Solving Skills Perception Scale of Primary School Students", "Scientific Creativity Scale", "Science and Technology Course Achievement Test" and "Student Opinion Questionnaire on STEM Applications". Considering the results of the analysis, it was observed that STEM applications contributed positively to 8th grade students' environmental attitudes, problem solving skills and science achievements. [This study was presented as an oral presentation at the 3rd International Eurasian Educational Research Congress (EJER-2016), Turkey.]