Green food consumption has become increasingly critical in the context of sustainable development and public health, particularly in emerging economies like Vietnam. Despite rising awareness, adoption of green food remains limited, partly due to gaps in understanding the behavioral drivers influencing consumer choices. This study addresses a key research gap by examining how electronic word-of-mouth (eWOM)—specifically its trustworthiness and frequency—alongside belief in green food benefits, subjective norms, and consumer attitudes, affect the intention to purchase and actual behavior of green food consumers in Hanoi. Prior research has not adequately explored how these digital and psychological factors interplay within the Vietnamese urban context. A quantitative survey was conducted with 589 residents in Hanoi, and data were analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). Findings reveal that all examined factors significantly and positively influence purchase intention, with frequency of eWOM exerting the strongest effect. Furthermore, purchase intention significantly predicts actual purchase behavior. These insights provide practical implications for stakeholders aiming to promote green food consumption and contribute to a more nuanced understanding of consumer behavior in digitally connected, urban environments of emerging markets.