This study aims at developing a measuring instrument of which validity and reliability for measuring the body images of individuals during adolescence and young adulthood are proven. The study group consists of 384 high school students. The content validity of the study was tested by seeking an expert opinion and the construct validity was tested by applying explanatory (EFA) and confirmatory (CFA) factor analysis. In the scope of analysis, IBM SPSS Statistics v20.0 and Lisrel 8.80 programs were used. As a result of EFA, a four-factor structure, which explains 62% of the total variance and is composed of 21 items, was obtained. The factors were called “Negative Perception of the Body”, “Evaluation Sensitivity”, “Positive Perception of the Body”, and “Body Change”. As a result of CFA, it was determined that the four-factor structure consisting of 21 items had an adequate fit index. As a consequence of reliability analysis, it was found that the Cronbach Alpha internal consistency coefficients, calculated for EFA and CFA samples, being .92 and .88 fell within acceptable values. The findings obtained following the item analysis demonstrated that the total score of items listed in the Body Image Scale presented a high level of predictive power and distinctiveness. The Body Image Scale can be defined as a valid and reliable measuring instrument to be used to measure the body image of adolescents and young adults.