This paper provides a detailed terminological definition of the organizational structure which is the main issue of this thesis. In this paper the key aspects of the organizational structure, differentiation and integration, which play an important role in its formation, are being discussed. A special chapter is dedicated to formal and informal organizations which form an integral part of every enterprise. Moreover, this paper also deals with the definition of the elements of organizational structure according to Henry Mintzberg and Mijo Novak. Regarding the formation of the organizational structure, the great importance have “topdown” and “bottom-up” approaches, bipolar strategy, wedge strategy, strategy of a large number of nuclei, division of enterprise’s overall task by five grounds according to Kosiol, so this paper provides their theoretical backgrounds and schematic diagrams. Another special chapter refers to the types of the organizational structure which are divided into traditional and organic. While functional, divisional, hybrid and mixed structure belong to the first category, projectbased, matrix and process-based organizational structure belong to the second one. Furthermore, the practical part of this thesis deals with the analysis of the organizational structure of Zagrebaĉka banka. The goal of this paper is to raise the awareness of the importance of the organizational structure and to analyse the organizational structure of any enterprise.