This study examines the influence of green marketing motivational factors on Algerian consumers' purchase intentions, specifically focusing on the mediating role of green brand trust in mitigating greenwashing's impact. The research, conducted in Maghnia, a city on the western border of Algeria, surveyed 262 consumers using a structured questionnaire. Analyzing the data using Partial Least Squares Structural Equation Modeling (PLS-SEM), the study reveals that green brand trust acts as a critical mediator between green marketing factors and purchase intentions. It finds that positive reception of green advertising and a strong green brand image significantly enhance green brand trust, which in turn, strongly influences consumers' intentions to purchase green products. Further analysis demonstrates that while non-deception and transparency do not directly impact green brand trust, they act as important moderators, enhancing the link between green advertising reception and trust. Notably, the study highlights the pervasive issue of greenwashing in Algeria, demonstrating how misleading environmental claims undermine consumer trust and purchase intentions. The study underscores the need for companies to prioritize genuine environmental efforts and ethical marketing practices to build lasting consumer relationships. Furthermore, the research emphasizes the importance of promoting environmental awareness among consumers through education programs and awareness campaigns, as well as strengthening environmental legislation to prevent deceptive practices. By understanding the complex relationship between green marketing factors, green brand trust, and purchase intentions, this study offers valuable insights for developing sustainable consumption patterns in developing economies while mitigating the negative effects of greenwashing.