The aim of the present research is to develop a psychometrically qualified measurement tool to find out the emotional authenticity levels of individuals. Taking roots from the rational approach, 53 items were written by the researchers in line with the relevant literature review and the opinions of the experts, and the expert opinion form prepared for these items was sent to 11 experts in order to calculate the content validity indices and ratio. In line with the opinions and suggestions from the experts, a 5-point Likert type trial form was created and applied to 408 individuals. 21.14% of them were found for "authentic behavior", 15.67% for "acceptance of external influence" and finally 15.46% for the "emotional avoidance" factor, respectively. The factor loadings of the scale vary between 0.41 and 0.81. In addition, confirmatory factor analysis was performed to test the construct validity of the scale. In line with these results, it can be said that the Emotional Authenticity Scale is a valid and reliable measurement tool.