PurposeGlobal interest in adopting the International Financial Reporting Standards (IFRS) has risen rapidly; however, the Middle Eastern and North African (MENA) countries have reacted differently towards the international diffusion. The purpose of this study is to examine the impact of the IFRS adoption/rejection decision on the quality of MENA region firms' financial reporting.Design/methodology/approachThe quality of accounting is examined through five metrics models to measure earnings smoothing, managing earnings towards a target and timely loss recognition. The research sample consists of nine countries over a period of ten years (2006–2015), resulting in 3,040 firm-year observations in the main phase, and 2,580 firm-year observations in the additional analysis.FindingsThe findings reveal that the overall sample of IFRS adopters in the MENA region has benefited from the adoption of IFRS, as the results show that there is a reduction in earnings management for IFRS adopters in comparison to local standards adopters. The sub-sample analyses also reveal that firms that adopted IFRS, in both the rentier (oil-dependent states) and non-rentier states, have a higher financial reporting quality than non-IFRS adopters. However, the magnitude of the financial reporting quality was higher for IFRS adopters in rentier states.Research limitations/implicationsSimilarly to previous research in this field, this study adopts a strict sample selection approach. Such an approach may limit the sample size, although the researchers have taken every possible step to ensure the use of an adequate sample size. The researchers acknowledge the strict period of ten years, despite having stated its rationale and importance of a more extended period to the quest of the paper.Practical implicationsThis research provides valuable input by evaluating the current status of MENA region firms' financial reporting quality, based on their followed accounting regime. The implications of this paper result in better-informed decisions for investors as the information contents of the annual reports enhance comparisons that facilitate the further flow of investments. This research also provides significant insight into the International Accounting Standards Board (IASB). The findings of this study will assist the IASB in understanding the MENA region by measuring the consequences of the countries' decisions on the quality of firms' financial reporting.Originality/valueThe findings of this study contribute to the literature by revealing that countries with medium levels of governance quality have benefited the most from the IFRS adoption, while IFRS adopters in countries with stronger governance quality demonstrate lower financial reporting quality.