1 THE RELATIONSHIP BETWEEN ETHICS, EXPERTISE, AUDIT EXPERIENCE, FRAUD RISK ASSESSMENT AND AUDIT SITUATIONAL FACTORS ON AUDITOR PROFESSIONAL SCEPTICISM Rita Anugerah Ria Nelly Sari Rina Mona Frostiana Department of Accounting, Faculty of Economics, Universitas Riau, Indonesia Kampus Bina Widya Km 12,5 Sp Panam Pekanbaru 28293, INDONESIA ritaanugerah@yahoo.com Abstract This study aims to prove empirically the effect of ethics, expertise, audit experience, fraud risk assessment, and audit situtional factors on auditor professional scepticism. To test the hypotheses, a Partial Least Square analysis is applied to questionnaire survey data from 40 auditors from Audit Board of the Republic of Indonesia, Riau Province Representatives. As hyphotisized, the results revealed the existence of a significant and positive association between ethics, audit experience, fraud risk assessment and situtional factors on scepticism of auditors. Contrary to the hypothesis proposed, this study fail to give support to the influence of expertise on auditor professional skepticism. Discussion and implications of the findings and also suggestions for future research are discussed. Keyworsd: Ethics, Expertise, Audit Experience, Fraud Risk Assessment, Situtional Factors and Auditor Professional Scepticism.