To sustain their growth worldwide, luxury brands are increasingly adopting the codes of fast fashion. They continually introduce new designs that move quickly from the catwalk to stores to stay on-trend, resulting in short and constantly renewed collections. But does this fashionization impede luxury brands’ Corporate Social Responsibility (CSR) image? This article investigates this question building on the ephemerality–scarcity dual-route model. Findings from a first experiment involving a fictitious luxury brand show that fashionization increases both perceptions of ephemerality (negative route) and scarcity (positive route), with opposing resulting effects on the brand’s CSR image. Extending these results to a real-life luxury setting, findings from a second experiment show that the influence of fashionization on the brand’s CSR image is only mediated by the positive scarcity route. This study provides a number of noteworthy theoretical insights and relevant managerial implications for luxury managers involved in CSR communication.