This study discusses the effect of knowledge levels of green suppliers and customers on the green performance of organisations and the role of green information systems in this relationship. Four hypotheses were developed in the study. The research was carried out on textile companies operating in Bursa, Türkiye. Between August and September 2022, 495 surveys were collected. Green supplier and green customer knowledge levels have a positive and significant effect on organisational green performance. Green information systems fully mediate between green supplier knowledge and green organisational performance. However, green information systems partially mediate between green customer knowledge and organisational performance.