["Business Strategy and the Environment, Volume 35, Issue 5, Page 7363-7377, July 2026. ", "\nABSTRACT\nResearch on green human resource management (GHRM) largely emphasises internal drivers, with limited attention to external institutional influences. This study examines how institutional pressures shape the adoption of GHRM practices in Nigeria's oil and gas industry. Semistructured interviews were conducted, drawing on insights from 25 professionals working in the upstream (56%), midstream (36%) and downstream (8%) sectors. Findings reveal that coercive and normative pressures more strongly influence GHRM practices, such as recruitment, training and performance management than mimetic pressures. Evidence of decoupling emerged, with gaps between policy and practice, means and ends, structure and implementation, highlighting discrepancies between formal adoption and substantive enactment. By extending institutional theory to a developing‐country extractive sector, the study underscores the contextual nature of isomorphic pressures and the multilevel manifestations of decoupling, offering fresh insights into how external institutional constraints drive reactive rather than proactive GHRM adoption.\n"]