Business decision making and management are the most important business activities of a company in which information represents the key resource. Modern business is not imaginable without the use of a suitable information base, therefore in obtaining the necessary, quality and timely information, accounting information systems have an important role as an integral part of the entire information system of the company. The final result of data processing in the accounting information system represents accounting information in the form of financial statements that are distributed to end users. For successful management, it is necessary to consider all types of information and in the context of this paper, special attention is paid to quantitative, financial information as the final product of the accounting information system. In order for managers to be able to rely on the received information, it is necessary to ensure its quality and to be able to manage it. One way to achieve the quality of information and the entire system is to set up appropriate internal controls. The internal control system includes methods and procedures that are carried out in order to reduce potential mistakes and irregularities to an acceptable level, thus achieving the precondition for fulfilment the company's goals. The audit of (accounting) information systems is intended primarily to ensure the effectiveness of internal control systems, and then the effectiveness of all processes in the company. The purpose of conducting an audit as the most important form of supervision is to create added value for the company by providing support, advices and recommendations for improving and enhancing business. In conclusion, it can be said that the quality accounting information system with a built-in effective internal control system over which the continuous audit is performed, provides the company and other users a higher level of confidence in the safeness and reliability of information, which ultimately leads to a more successful decision making process.