This study examines the phenomenon of “promise inflation”, which has become increasingly visible in the marketing literature, from a conceptual and critical perspective. Brand promises constitute the core of the value proposition offered by a brand to consumers and function as strategic communication tools that play a decisive role in shaping consumer perceptions. Traditionally, brand promises have been considered important signals that facilitate consumer decision-making under conditions of uncertainty and support trust toward the brand. However, in today’s marketing environment, increasing competition, digitalization, and the accelerating pace of social media communication have led brands to produce more ambitious and comprehensive promises. As a result, although brand claims increase in quantity, the perceived credibility and distinctiveness of these promises gradually erode over time. In this study, promise inflation is defined as the process through which the perceived value and credibility of brand promises diminish as brands continuously expand the scope and level of their claims in order to gain competitive advantage. The effects of this phenomenon on consumer perception are examined within the framework of concepts such as declining perceived credibility, promise fatigue, and erosion of brand trust. Furthermore, promise inflation is discussed in the context of marketing ethics, evaluating how the boundary between legitimate persuasion and excessive promises becomes increasingly blurred. The study also addresses strategic approaches to prevent promise inflation. Developing realistic and evidence-based promises, ensuring consistency between brand communication and consumer experience, adopting the principle of transparency, and applying moderation in communication emerge as critical factors for building sustainable brand trust. Consequently, the study emphasizes the necessity of a marketing approach that focuses not on the quantitative expansion of brand promises but on their qualitative sustainability.