Indonesia has committed to reaching Net Zero Emissions in 2060. PT PLN (Persero) is a company prioritizing utilizing clean energy to fulfill power demand. The four- eyes principle must be implemented in making strategic decisions to ensure that decision- making at PT PLN (Persero) complies with the regulation. This mechanism is embedded in the three lines of the Defense model. As the third line, Internal Audit is responsible for performing audits and consulting on implementing internal control, risk management, and governance. There are four competencies framework that Internal Audit needs to have. They are professionalism, performance, environment, leadership and communication. This research is carried out on the understanding and role of Internal Audit on the energy transition conducted in qualitative and quantitative methods. The qualitative is done through a questionnaire survey, and the quantitative is carried out through interviews.The research results show that the Internal Audit understands what the energy transition is and the Internal Audit's position in the energy transition. However, the Internal Audit still needs more understanding regarding energy transition in some aspects. It also shows that the realization of the roles of Internal Audit still needs to be improved to ensure the program that has been carried out complies with the rules.Moreover, the information regarding the energy transition that gets by Internal Audit still needs to be improved. Therefore, this research recommends maximizing the information about energy transition in Internal Audits through training, knowledge sharing, and direct contribution to energy transition through collaboration.