This paper contributes to extant research on green human resource management (HRM) relying on the instrumental value of stakeholder theory, which implies that stakeholders impact on company decisions and their development of organizational resources and performance. Following that theory, the study conceives green HRM practices as a set of management processes that companies implement for responding to stakeholder pressures on environmental issues. Accordingly with those premises, we empirically test the distinct role that different green HRM practices (i.e. green hiring, green training and involvement, and green performance management and compensation) play in mediating the relationship between pressures on environmental issues from two specific external stakeholders (i.e. customers and regulatory stakeholders) and environmental performance. Our findings, based on a multi-respondent survey in which the respondents were Human Resource Managers and Supply Chain Managers operating in Italy, confirm the hypothesized mediation model. Our results (as well as their implications) are discussed in light of the recent calls to broaden the scope of HRM research, considering the embeddedness of the company in a socio-political context and exploring the role that actors and factors outside the company play in shaping its green HRM practices.