ABSTRACT Employee green behavior is a necessary condition for organizations to achieve sustainable success. Drawing upon self‐determination theory, this paper thoroughly investigates the mechanism through which a synergistic combination of multiple antecedents’ influences employee green behavior via qualitative comparative analysis. The findings reveal that no single factor constitutes a necessary condition for high employees' green behavior. However, organizational identification and green self‐efficacy play crucial roles in fostering such behaviors. We identify three equivalent pathways for promoting employees' green behavior, namely, “synergistic internal and external environmental orientation,” “psychological climate driven by organizational identity,” and “internal environmental orientation under environmental regulation.” Furthermore, this study uncovers the complementary nature of organizational identity and employee self‐efficacy, as well as the substitutability of internal and external environmental orientation. These findings suggest that organizations should focus on fostering a strong organizational identity and enhancing employees' self‐efficacy while maintaining a balance between internal and external environmental orientations to effectively promote green behavior among employees.