This study examines how Instagram advertising through influencers impacts consumer brand awareness and purchase intent, with a particular focus on the Vietnamese market. While prior research highlights influencer marketing as a growing trend, limited attention has been given to the mediating role of brand awareness in shaping purchase decisions. Using a mixed-methods approach, qualitative expert discussions and a quantitative survey of Instagram users in Ho Chi Minh City were conducted. Findings reveal that influencer credibility—defined by attractiveness, trustworthiness, and expertise—significantly enhances brand awareness, which in turn increases purchase intent. The study contributes to understanding the dynamics of influencer marketing in emerging markets and provides practical insights for marketers seeking effective Instagram advertising strategies.