The study aimed to test the role of planning in detecting the significant irregularities in the financial statements of the clients in the audit companies and firms, where the research came to provide a knowledge about the concept of planning an it‟s activities, beside its role in increasing the ability of the auditor in detecting the significant irregularities in the financial statements of Clients. In this context, the research community is determined as audit companies and firms, a sample of (60) individuals that are working in the field of auditing in Damascus companies and firms were picked up, finally the researcher reach to a group of conclusions: 1. There is a significant positive correlation between obtaining information about the customer and detecting the significant irregularities in the financial statements of clients. 2. There is a significant positive correlation between obtaining the information of the legal obligations of the client and detecting the significant irregularities in the financial statements of clients.. 3. There is a significant positive correlation between the implementation of the initial analytical procedures and detecting the significant irregularities in the financial statements of clients. 4. There is a significant positive correlation between the assessment of materiality and detecting the significant irregularities in the financial statements of clients.. 5. There is a significant positive correlation between audit risk assessment and detecting the significant irregularities in the financial statements of clients..