The extent to which external auditors rely on the work of internal auditors is an important judgment. Recently, the Public Company Accounting Oversight Board has recommended that external auditors “rely (more) on the work of others” to reduce the greater-than-expected costs associated with compliance with Section 404 of the Sarbanes–Oxley Act. Reliance decisions, however, are complex decision tasks that require professional judgment and may be influenced by a number of factors, both external (environmental) and internal (cognitive and affective), including the auditors' working style and pervious experiences related to barriers to external/ internal auditor cooperation (e.g., previously experienced low versus high internal auditor objectivity and/or competence). We experimentally examine these influences in our research reported herein. Consistent with expectations, external auditors' work styles significantly influenced the extent of planned audit testing, internal auditor reliance judgments, and interpretation of analytical procedures results. Auditors' perceptions about internal auditors' competence and objectivity, developed over years of interaction, also influenced these judgments, and interacted with work styles. Inconsistent with expectations, auditor
rank (senior versus manager) did not influence judgments.