Increasingly, companies are embracing the green‐lean‐six sigma (GLSS) approach to managing their environmental impacts. Nevertheless, there is a paucity of studies that examined the underlying motivations behind GLSS deployment in manufacturing organizations. Accordingly, this study investigates the GLSS motivators in a developed and developing economy context through multiple case studies in which semi‐structured interviews are conducted with senior corporate managers in the flexible packaging manufacturing industry. Drawing on the natural resource‐based view (NRBV) and institutional theory‐based view (ITBV), our analysis revealed various operational, organizational, and environmental factors as internal motivators and factors related to the state, society, and market as external motivators. To the best of our knowledge, it is one of the early comparative studies investigating the GLSS motivators in both developed and developing economies, which can guide future researchers, practitioners, and policymakers in understanding the salient factors influencing the GLSS adoption for environmental sustainability.