In reviewing existing literature, scales that deal with peer relations' communicative effectiveness dimension within an educational context were not found. The purpose with this research was to develop a scale for communicative effectiveness of peer relationships for students. A total of 670 students from public/private high schools in Northern Cyprus were selected for this purpose. Using the high school education system in Northern Cyprus, results of scale validity and construct validity tests successfully validated the instrument for "communicative effectiveness of friend relationships." Cronbach's alpha coefficient of 0.835 confirmed the validity and reliability of the instrument used in the study. From the results of the exploratory factor analysis, this research provides an instrument with 10 different dimensions to predict the educational communication effectiveness of students. The study validated and loaded 10 of the 42 items. As a result, the findings demonstrate that the peer interaction scale developed in this study was appropriate for gauging high school students' overall communicative effectiveness.