The purpose of this study is to assess the ecological efficiency of manufacturing small and medium-sized enterprises (SMEs) by analyzing their adoption of green human resource management practices (GHRMPs), green intellectual capital (GIC), and green innovation (GIN). The study was carried out on a representative sample of 367 manufacturing SMEs in Pakistan, and data were gathered using a particular survey questionnaire. The results were analyzed using the partial least squares–structural equation modeling (PLS-SEM) technique in SmartPLS4. This research indicates that the adoption of GHRMPs significantly impacts environmental performance (EP), GIC, and GIN. Additionally, the study found that the correlation among GHRMPs is positively mediated by GIC and GIN. The study contributes to the body of knowledge by investigating EP based on the Ability-Motivation-Opportunity Theory (AMO) through empirical evidence on hypothesized relationships. The paper provides a valuable understanding and novel approach for managers of SMEs in developing countries to improve their EP through the adoption of GHRMP, GIC, and GIN.