professional ethics is one of the long - term pillars in the field of accounting that has a direct impact on maintaining public trust , transparency in financial reporting and preventing fraud . considering the increase in fraud and misrepresentation in financial statements in recent years and its economic and social impacts , it is important to investigate the role of professional ethics of accountants in reducing this phenomenon . the purpose of this study is to evaluate the effect of professional ethics of accountants on پیشگیری of fraud and defect in financial statements and to identify factors affecting the adherence of accountants to ethical principles . this study is descriptive - survey and with quantitative approach . the data were collected through a questionnaire designed by the researcher using a 5 - point likert scale . the study population consisted of accountants , auditors and financial managers working in iranian organizations and a sample of 50 people was selected through available sampling method . descriptive statistics including frequency , percentage and mean were used to analyze the data . the results show that according to respondents view , professional ethics observance has a significant effect in reducing the probability of financial fraud , preventing deliberate change of numbers and increasing reliability of financial statements . the results also show that although there is a belief in fundamental ethical principles such as honesty and impartiality , there are challenges in some operational principles such as confidentiality and full compliance with standards . in general , this study emphasized that the enhancement of professional ethics of accountants , along with improving the organizational and regulatory mechanisms , can help improve the quality of financial reporting , effectively reducing fraud and increasing the trust of the stakeholders .