Purpose: This study aims to evaluate the effect of Instagram’s short video clips on the purchase intentions of Vietnamese Gen Z consumers. The respondents are demographically aged 18–26 in Ho Chi Minh City of Vietnam. The research investigates how features such as Reels, Stories, and shopping integrations influence purchasing behaviours while identifying trends and patterns associated with short video consumption. By shedding light on these dynamics, the research seeks to provide valuable insights into the digital behaviours of Vietnamese Gen Z and the growing role of social media marketing in shaping consumer’s purchase intention. Research Design, Data and Methodology: A pilot study (N = 100) refined the questionnaire using Cronbach’s Alpha and Exploratory Factor Analysis (EFA). The official study (N = 291) employed a 5-point Likert scale and collected data via online surveys distributed on Instagram. Convenience sampling targeted Gen Z aged 18–24 who are frequently watching short video clips on Instagram. Results: The results suggest five factors affecting purchase intention (IST): Interesting Content (IC), Price Discount (PD), Informativeness (IF), Perceived Enjoyment (PE), Scenario-based Experience (SE), and Feedback from Users (FB). These factors collectively influence Vietnamese Gen Z’s intention to purchase on Instagram through their engagement with short videos.