Purpose This study aims to investigate the relationship between green human resource management (GHRM), corporate social responsibility (CSR) and organizational performance (OP) of small- and medium-sized enterprises (SMEs) by examining corporate reputation (CR) and employee engagement (EE) as mediators in Vietnam. Design/methodology/approach This study used the quantitative method with 458 valid responses from mid- to senior-level managers and chief executive officers (CEOs) were obtained and used for data analysis. To analyze and explore the relationships between constructs and mediators, SmartPLS version 4.0 structural equation modeling was used to analyze the data of the SMEs of Vietnam in 2023. Findings The results showed strong and positive relationships between GHRM, CSR and OP in SMEs, with CR and EE serving as significant mediators. Originality/value This research provides new insights into how GHRM and CSR enhance OP by using an integrated model that examines how CR and EE mediate this relationship. It demonstrates that businesses implementing GHRM and CSR can promote sustainable development among stakeholders, leading to improved OP in Vietnam’s dynamic economic environment. The findings have practical implications for executives and managers, emphasizing the need to balance stakeholder, environmental and social interests to optimize GHRM and CSR initiatives and foster sustainable growth. This study’s insights could significantly influence SMEs in the Vietnamese economy.