This study examines the effects of brand trust and green marketing on repurchase decisions among Generation Z consumers of fast fashion products, with customer satisfaction serving as a mediating variable. Drawing on the Theory of Planned Behavior (TPB), this study proposes that brand trust and green marketing foster favorable consumer evaluations and strengthen Generation Z consumers’ willingness to repurchase fast fashion products. Customer satisfaction is further expected to mediate these relationships by reinforcing consumers’ confidence in their purchasing decisions and encouraging continued repurchase behavior. This study employs a quantitative approach using Structural Equation Modeling (SEM) with the Partial Least Squares (PLS) technique. The findings demonstrate that brand trust significantly and positively influences both customer satisfaction and repurchase decisions. Similarly, green marketing has a significant positive effect on customer satisfaction and repurchase decisions. Customer satisfaction also positively and significantly influences repurchase decisions. Furthermore, customer satisfaction significantly mediates the relationships between brand trust and repurchase decisions, as well as between green marketing and repurchase decisions. These findings suggest that fast fashion brands can strengthen Generation Z consumers’ repurchase decisions by building brand trust, implementing credible green marketing practices, strengthening digital communication, and developing sustainability-oriented loyalty programs that enhance customer satisfaction.