The current research aims to show the impact of the international auditing standard IAS 540 in reducing income smoothing practices in Iraq. To achieve the objectives of the research, the researcher adopted a questionnaire for a sample of auditors in Iraq. Where 60 forms were distributed and after the questionnaire was retrieved and statistical analysis was done using the SPSS program, The research reached a number of results, the most important of which are: the existence of a statistically significant effect of the application of the international auditing standard IAS 540 in reducing income smoothing practices, The research recommended the necessity of training and developing the skills of auditors in Iraq in order to understand the requirements of the auditing standard IAS 540 "Auditing Accounting Estimates and Related Disclosures" because it includes a set of guidelines and practices that help reduce the manipulation of accounting estimates and consequently the inability of management to practice the income smoothing process