There have been a number of studies examining audit fees and this research has covered various nations. Recent legislation in Norway requires a company to disclose information on the audit fee and the fees for non-audit services paid to its auditor. Using this data, models of audit fee structure are developed. As with other studies, the size of the company is a major determinant of the audit fee. Payments for non-audit services are positively and significantly associated with audit fees; this relationship is difficult to explain although it parallels some research in the United States. Overall, the models explain about 75 per cent of the variability in audit fees.