The presence of an internal audit area, in keeping with the empirical studies reviewed, may have a positive or negative relationship with the cost of the audit service. The negative sign is explained by the risk effect because the internal audit service can reduce the external auditor's risk of service provision. A positive relationship indicates the predominance of the demand effect, where better organized companies require more specialized analysis from their external auditors. In the analyzed sample, the variable that identifies the presence of an internal audit department (DENTAL) shows a negative relationship with audit costs, although it is not statistically significant