Abstarct: This study aimed to investigate the effect of green human resource management practices on the sustainable performance of manufacturing knowledge-baxsed firms, with particular emphasis on the mediating roles of green intellectual capital and green innovation and the moderating role of sustainable leadership. In terms of purpose, the study was applied, while methodologically it followed a descxriptive-correlational and cross-sectional research design. The statistical population consisted of senior, middle, and operational managers working in manufacturing knowledge-baxsed firms located in Tehran Science and Technology Park. The final sample included 324 managers from 108 firms. Data were collected through a standardized questionnaire using a five-point Likert scale and analyzed at both descxriptive and inferential levels using SPSS and SmartPLS. Partial least squares structural equation modeling was employed to assess the measurement and structural models. The measurement model results confirmed satisfactory internal consistency reliability, convergent validity, and discriminant validity. The structural model findings demonstrated that green human resource management practices had positive and significant effects on green intellectual capital, green innovation, and sustainable performance. Green intellectual capital also positively influenced green innovation, while green innovation significantly enhanced sustainable performance. The mediation analysis revealed that green intellectual capital partially mediated the relationship between green human resource management practices and green innovation. Moreover, green innovation partially mediated the relationship between green human resource management practices and sustainable performance and fully mediated the relationship between green intellectual capital and sustainable performance. Sustainable leadership positively and significantly strengthened both the relationship between green human resource management practices and green innovation and the relationship between green intellectual capital and green innovation. The coefficients of determination for green intellectual capital, green innovation, and sustainable performance were 0.209, 0.414, and 0.400, respectively, while the overall goodness-of-fit index was 0.435. The findings indicate that developing green human resource systems, converting environmental knowledge into innovative products and processes, and strengthening sustainable leadership can substantially improve the economic, social, and environmental performance of manufacturing knowledge-baxsed firms.