Social media has evolved from text to visual content and is utilized in marketing by fashion brands. Social media marketing enables interactive relationships with consumers and influences purchasing decisions, although its effectiveness is still debated. This study analyzes the impact of social media marketing features on purchasing decisions, with Brand Trust as a mediating variable. The research employs a quantitative questionnaire based on six main variables: Interactivity, Informativeness, Entertainment, Perceived Relevance, Brand Trust, and Purchase Decision. Data were collected from 200 respondents selected via purposive sampling, with the criteria of being active on social media and purchasing Erigo products. Data analysis includes pre-processing, classical assumption testing, Confirmatory Factor Analysis, Goodness of Fit testing, and hypothesis testing using SEM to examine the relationships between variables. The results indicate that purchasing decisions for Fashion Brands are directly influenced by interactivity and brand trust and indirectly by relevance, entertainment, and informativeness through the mediation of Brand Trust. These findings emphasize the importance of relevant, informative, and entertaining content strategies to build brand trust. The contribution of this research lies in understanding the mediating relationship of brand trust in the context of social media and fashion consumer behavior, offering practical guidance for brands to optimize digital marketing strategies to enhance consumer purchase decisions through meaningful social experiences.