Implementation of Good Corporate Governance (GCG) in an organization is essential for the survival of the company. An activity in a period is necessary to evaluate and to monitor the organization's performance improvement at future. One effort to monitor the performance of the organization in order to align the planning and execution of the work carried out a monitoring and control. In order to achieve such alignment, it is necessary to control the unit's internal control system procedures that include both tangible and intangible substance control. Auditing International Standard Operation (ISO) and the Satuan Pengendalian Internal (SPI) in its implementation involves several internal auditor, where there are still some obstacles that organizations face in putting an auditor in the organization, including the diverse educational background, is still a lack of understanding of the code of ethics auditors and organizations, which have not been standardized auditor competence impacting the auditee complaints over the decision and recommendation. The purpose of this study was to determine the effect of individual factors (audit experience, professional commitment, and ethical orientation) and situational factor (organizational ethical values) on ethical decision making of internal auditors. The population in this study are all UT internal auditors that includes an ISO internal auditor and the auditor SPI-UT UPBJJ operational areas. This study analyzes the data using multiple linear regression method. The results showed that individual factors significantly influence ethical decision making of internal auditors. The dominant factor is the effect of audit experience as an individual factor and ethical values as a situasional factor in ethical decision-making organization.