Abstract: The study aims to investigate the impact of firm characteristics on the extent of implementation of the Interim Financial Reporting standard (IAS 34) for listed firms in GCC stock markets using several firm characteristics (firm size, firm foreign operations, firm profitability, firm age and firm industry). The study provides empirical evidence on the implementation of the international accounting standard 34 in GCC countries, which can extend previous literature related to this important area of accounting research. The sample used in this study consists of 454 firms listed in GCC stock markets with a total of 984 firm-year observations for the financial years from 2017 to 2019. Results are obtained by using SPSS program. At the same time, the multiple regression analysis is used to examine the impact of firm characteristics on the extent of the implementation of the Interim Financial Reporting standard (IAS 34). The overall findings confirm the theories related to this topic and show a considerable connection between firm characteristics and implementation of the Interim Financial Reporting standard (IAS 34). Findings reveals that firm size, firm foreign operations and firm age significantly impact the extent of implementation of the Interim Financial Reporting standard (IAS 34). However, the other two independent variables, firm profitability and firm industry not significantly impact the extent of implementation of the Interim Financial Reporting standard (IAS 34). Accordingly, the study recommends that auditors and accountants should focus more on the international accounting standards related to interim reporting. Regulators should issue laws that enforce firms to prepare interim financial reports continuously. In addition, investors and other stakeholders should be aware about the disclosed information in the financial reports and take indications linked to investing in the firm. Keywords: International Accounting Standard 34, Interim financial reporting, Gulf Cooperation Council countries, Firm characteristies, Firm foreign operations.