The article examines how internal audit impacts good corporate governance and influences external audit processes and fees through a thorough literature review. It finds that internal auditors play a crucial role in ensuring financial statement accuracy, regulatory compliance, and advising on operational effectiveness. The effectiveness of external audits depends on factors like internal audit quality, coordination between internal and external auditors, risk levels, and fee determinations. In essence, a high-quality internal audit function positively affects both external audits and audit fee decisions.