<p>The individual effects of green accounting and intellectual capital on firm performance are well established; however, their synergistic impact on firm Value, particularly in emerging economies, remains inadequately researched. This study examines the relationships between green accounting, intellectual capital, and firm Value, with sustainable development as a mediating variable, using evidence from the MIG in Ethiopia. Following purposive selection, the population was stratified by department and job level, and a census of all 316 eligible professionals was conducted. Analysis was performed using PLS-SEM (SmartPLS 4), with mediation validated through 5000-sample bootstrapping. The findings reveal a dual-pathway to firm value. Intellectual capital emerges as a primary driver, exerting a strong positive influence on both sustainable development and firm value. In contrast, while green accounting directly enhances firm value, it demonstrates a significant negative impact on sustainable development; this counterintuitive relationship reveals an accounting asymmetry where immediate compliance costs are documented on balance sheets while long-term strategic circular values remain off-book. Consequently, green accounting functions as a resource intensive cost center rather than an immediate strategic sustainability driver. Furthermore, sustainable development serves as a critical mediator, partially channeling the effects of both variables into long-term value. The study highlights a sustainability paradox where financial gains from green accounting do not immediately translate into broader sustainability outcomes. These results underscore the need for firms in developing economies to move beyond regulatory compliance and integrate intellectual capital to bridge the gap between reporting and genuine sustainable impact.</p>