Accounting Standard No. 42 with the title of fair value accounting is one of the main and most important topics in the field of financial accounting and has economic and accounting importance; Despite the importance of fair value accounting and the criticisms made to this standard, the challenges and Post Implementation Review of this standard have not been investigated so far. This research was conducted with the aim of evaluating the Post Implementation Review of standard 42 using the quantitative research method; The statistical population of the research includes financial statement preparers, users, auditors and university professors. In this way, the research data was collected using a researcher-made questionnaire that was purposefully distributed among the sample members; The questionnaire was collected and tested and statistically analyzed using factorial and exploratory techniques. The findings of the research show that the explanations and inherent complexities of the fair value standard, the high cost of implementing the standard, the usefulness of the notes related to the standard and the non-operational implementation of the standard are among the most important challenges of using fair value in the reporting environment of Iran. Updating the figures of the statement of financial position, reflecting the market consensus about the economic value of assets and liabilities, the ability to compare financial statements and the ability to predict profit have been among the most important opportunities for implementing the fair value standard.