Brand authenticity is generally considered to have a direct impact on brand loyalty. However, few studies have investigated the mediating variables between them. To add to our knowledge in this area the present study examines how brand authenticity (the four dimensions of symbolism, credibility, integrity, and continuity) influences self-enhancement values (including achievement and power) and brand attachment, the antecedents to brand loyalty in chain coffee shops. This important research is carried out in the context of stimulus-organism-response (SOR) theory. The study surveyed chain coffee shop customers and a total of 410 valid responses were collected in December 2020. These were analyzed using the SPSS and AMOS statistical packages. A SEM (Structural Equation Modeling) analysis showed that all four brand authenticity elements were reliable and successful predictors of self-enhancement, which in turn leads to brand loyalty. Furthermore, all the symbolism, credibility, integrity, and continuity dimensions had a more significant impact on perceived power than achievement. Self-enhancement and brand attachment also contributed significantly to brand loyalty. Moreover, the importance of perceived achievement and power mediated the effect of brand authenticity on brand attachment. Based on these findings, this study provides important information for the management of affordable luxury service brands of coffee and other products.