The modern approach to public sector management represents a significant change in the way public services are organized, delivered, and evaluated. This approach, known as New Public Management, applies to private sector management techniques with the aim of increasing efficiency, accountability, and the quality of public services. It emerged in the 1980s as a response to the perceived inefficiency of the traditional bureaucratic management model, which was overly centralized and burdened with formalities. The modern approach includes decentralization, results orientation, and the application of market principles in the organization of public services, aiming to achieve greater flexibility, transparency, and better focus on the needs of citizens. The purpose of this paper is to explore the key aspects of New Public Management, its development, and its implementation in various countries, with a particular focus on the Republic of Croatia. The paper is analysing the fundamental goals and principles of New Public Management, as well as the techniques and measures that accompany its application in public administration reforms. By comparing different international models, such as the British, German, American, and Danish models, the aim is to provide a comprehensive overview of the approaches and practices that have shaped modern public sector reforms. The paper also addresses the specifics of implementing New Public Management in Croatia, exploring the challenges and opportunities arising from adapting this model to local conditions. This paper not only analyses the techniques and process of implementation but also reflects on the long-term effects of these reforms on Croatian public administration, with the goal of identifying key factors of success or failure. It will discuss the necessity of further development of public management in Croatia, emphasizing the importance of balancing market principles and social goals to maintain the quality and availability of public services.