This research aimed to understand and examine the effect of green human resource management (GHRM) practices on sustainable university (SU) performance in the ten largest private universities in Indonesia. The implemented sustainable performance was mediated by green psychological climate (GPC) of academic and non-academic staff (lecturers and educational staff). This research used quantitative method, with data collected through questionnaires distributed to 382 respondents. Partial Least Square Structural Equation Modleling (PLS-SEM) was adopted for data analysis and hypothesis testing. Meanwhile, the data analysis tool used SmartPLS version 4. The results showed that all hypotheses proposed statistically lead to a positive and significant effect between GHRM, GPC, and SU. Practical implications This research assisted university stakeholders in understanding that the implementation of GHRM practices, accompanied by building GPC, could effectively drive the realization of SU performance. Originality/value References were also added regarding the identification of GPC as a mediator in the relationship between GHRM and SU. GPC, as a mediator was incorporated, affecting the relationship between the effectiveness of GHRM practices and the achievement of SU performance.