The aim of this study is to investigate sixth grade students' academic achievement and their attitudes towards STEM practices applied in the unit of "Force and Motion" of science course book. In the study, experimental research design with randomly selected pre-test post-test groups was employed. The study was conducted with sixth grade middle school students enrolled in a state school in Hakkari in 2018-2019 academic year fall term. A total of 40 students were included in the study. STEM practices developed in accordance with STEM lesson plan were done with experimental group students. As for control group students, lessons were carried out according to the lesson plan on the curriculum. Validity and reliability of Academic Achievement Test applied to both experimental and control group students as pre-test and post-test was tested and Cronbach alpha level was found as 0.84 post-test. Both groups were also administered STEM Attitude Scale as pretest and post-test. Validity and reliability of STEM Attitude Scale was tested, and Cronbach alpha level was found as 0.905. The quantitative data of the study was analysed on a statistical package program. Results indicated an improvement in experimental group students' academic achievement, attitudes, and opinions on STEM practices.