The topic of this thesis is the contemporary aspects of the organisation of internal audit in organisations. Internal audit plays a key role in corporate governance as it ensures the transparency of business processes and contributes to effective decision-making. The thesis thoroughly examines fundamental concepts such as audit, internal audit and internal control and other related concepts that are critical to the establishment and successful functioning of internal audit. The aim of this thesis is to examine and analyse the essential elements and modern approaches to the organisation of internal auditing as a vital process in companies. The focus is on understanding the theoretical and practical aspects of internal auditing, its role in strengthening corporate governance, improving organisational efficiency and ensuring compliance with the relevant legal and regulatory frameworks. The purpose of internal audit in an organisation is to continuously support management in making informed and strategic business decisions. As an independent and objective function, Internal Audit assesses the effectiveness of risk management systems, control processes and governance practises. This ensures that the company's strategic objectives are achieved in accordance with best practise and legal requirements. In addition, Internal Audit plays a key role in promoting organisational accountability and transparency, which contributes to the long-term success and sustainability of the company.