The aim of this study was to investigate an application of interdisciplinary teaching approach. It was a case study that supported by combination of qualitative and quantitative methods. Thirty-four 10th grade students who were attending a private school in Ankara were asked to develop projects in the line of interdisciplinary approach. To detect the effectiveness of this approach, a logical thinking skills test (GALT) was administered as pre-post test single-group experimental design fashion. To learn about students’, teachers’, and parents’ ideas about the application, two interviews (before and after the application) were conducted. In addition, a questionnaire about interdisciplinary teaching approach was administered to all teachers at the school (N=36). The results obtained from pre-post test scores of students revealed that there was a significant difference in favour of the application. The interview data showed that teachers, students and parents had positive thoughts about the process. All of them agreed that interdisciplinary projects contributed to development of the ability of making connections between previously learned concepts, transferring what has been learned, and using the computer effectively as well as development of problem-solving, logical thinking, and communication skills.