This study discovered the impact of environmental knowledge, electronic word-of-mouth (eWOM), and green marketing on purchase intention for LocknLock products, mediated by environmental care attitudes and green brand image. This study is motivated by the global plastic waste crisis and Indonesia's high contribution to marine waste, as well as increasing consumer interest in sustainable products. This study seeks to assess the dynamics of these factors within a specific brand context, addressing gaps in existing literature by integrating green brand image as a mediator, while providing recommendations for environment-based marketing strategies and insights into sustainable practices for emerging markets. The theoretical framework of this study integrates the Norm Activation Model (NAM) and Affect-Behavior-Cognition (ABC) theory to explain the relationship between environmental awareness, attitudes, and consumer behavior. Literature review reveals that green brand image and environmental care attitudes are critical mediators yet underexplored in household brands like LocknLock. Hypotheses were designed to test direct and indirect relatiionships between independent variables and purchase intention. A quantitative approach with Structural Equation Modeling (SEM) via SmartPLS was employed. Data were obtained via online survey questionnaires from 400 Indonesian consumers familiar with LocknLock. All variables were measured on a five-point Likert scale, and evaluated using validity and reliability assessments, followed by path analysis to assess the structural relationships.Variables were measured using a 1-5 Likert scale, with validity, reliability, and path analysis to verify the research model. This study found that green marketing significantly influences purchase intention directly (? = 0.264) followed by Environmental Knowledge (? = 0.250) and eWOM (? = 0.157). This model explains 68.4% of the variance in purchase intention, which, showing that direct effects are more impactful than indirect ones, emphasizes the importance of integrating green strategies and authentic brand communication. The study concludes the integration of environmental education, digital campaigns, and sustainability initiatives can enhance consumer loyalty. Practical recommendations include evidence-based eWOM content, collaborations with environmental communities, and eco-friendly packaging innovation. Future studies could test different sectors, apply other methods, utilize various theories and add more control factors or mediators to see if the relationships are the same in various circumstances. Keywords: Environmental knowledge, eWOM, green marketing, purchase intention, environmental care attitudes, green brand image