Main aim of this study is to examine the influence of computer-assisted roundhouse diagrams on high school 9th grade students' academic achievements in the subjects of "Force and Motion". The study was carried out in a public high school in Diyarbakir the province in the Southeast of Turkey. In the study, the "pre-test-post-test control group model", which is among experimental models, was applied. The lessons were taught to the control group students by carrying out the activities previously determined in the curriculum; in other respects, besides these activities, the lessons were taught to the experimental group students by forming roundhouse diagrams that included the subject-related concepts. In the present study focusing on the subjects of "Force and Motion", a multiple-choice achievement test consist of 20 questions related to the subjects of "Force and Motion" was applied as pre-test and post-test to the students to determine the changes in their achievements. The study showed that computer-assisted roundhouse diagrams have significant effect on students' academic achievement in the subjects of "Force and Motion" (P < 0.05). Besides the multiple-choice test used, another test of 20 fill-in-the-blank and true-false questions was applied as pre-test and post-test in the study. According to the results of this test, the scores of the participants were found high in favour of the experimental group (P < 0.05). In addition to these two tests measuring the academic achievements of the participants, a questionnaire for the experimental group students' views about the roundhouse diagrams was conducted. As a result of the analysis of the data obtained via this scale, it was found out that the students enjoyed studying with the roundhouse diagram and that they considered the roundhouse diagram as a beneficial method in learning concepts.