<p>Organizations are increasingly encouraged to embed green business practices into their core operations as a means of enhancing sustainability performance rather than addressing them as isolated initiatives. Yet, their precise contribution to firm-level sustainability outcomes remains understudied, especially in emerging economies. Drawing on Transformational Leadership Theory and Self-Determination Theory, this study examines how Environmental Transformational Leadership (ETL) is associated with employee green behavior through a sequential psychological mechanism. Survey data from 216 public sector employees were analyzed using SmartPLS (v4.1.1.5). Results indicate that ETL has a significant positive total effect on employee green behavior; however, its direct effect on autonomous environmental motivation is statistically insignificant. Instead, ETL is associated with the fulfillment of employees’ psychological needs for autonomy, competence, and relatedness; this needs fulfillment is associated with higher levels of autonomous environmental motivation, which in turn is associated with green behavior. The identified sequential pathway clarifies the omitted variable bias noted in earlier work and enriches Self-Determination Theory by positioning need satisfaction as an indispensable precursor to intrinsic environmental motivation. These insights advance environmental leadership research and contribute primarily to United Nations SDG 12 with relevance to SDGs 13 and 15 by illuminating a psychologically grounded pathway through which ETL is linked to sustainable workplace behavior.</p>