This paper reviews the existing literature on formal accounting harmonization processes, particularly emphasizing the initial adoption of the International Financial Reporting Standards (IFRS) in European countries. It explores the advantages and disadvantages of accounting harmonization, the challenges faced during its implementation, and the benefits it provides. A literature review was conducted to achieve the proposed objective, analysing studies on the effects of accounting harmonization, particularly the adoption of IFRS, across different countries and jurisdictions. The review identifies the advantages and disadvantages associated with implementing these standards. We conclude that the main advantage of accounting harmonization, as highlighted in the literature, is improving the quality of financial reporting. This results in more market-relevant earnings and timely loss recognition, given that IFRS standards are principles-based. However, the process also presents several disadvantages, such as increased operational costs, the need for specific software to support the more complex accounting system, and costs associated with employee training and recruitment. On the other hand, the benefits often include reduced operational costs for multinational corporations, lower capital costs, and increased foreign direct investments. The outcomes of accounting harmonization processes are generally influenced by the adopting country's legal system and the internal incentives of the adopting entities.