We examine the relationship between internal governance, external audit monitoring and regulatory oversight for a sample comprising industrial companies and financial/utility companies subject to additional industry-specific regulation. Our results indicate that the association between audit fees and board/audit committee independence and size are weaker for regulated companies. These observations are consistent with the notion that regulatory oversight partially substitutes the external audit as a monitoring mechanism. However, boards/audit committees with more multiple directorships demand a more extensive audit in the presence of regulatory oversight to protect their reputation capital. Our study enhances our understanding of the complex relationships among the major corporate governance elements.