In this graduate thesis a discussion was made on the importance of organizational structure in large companies. The large companies used as comparisons and the subject of research in this paper were companies in Zadar County. The importance of the organizational structure is presented through an explanation of the type of structure and research carried out on the companies surveyed. Choosing an adequate organizational structure is just one of the many challenges posed to modern companies. When selecting the structure, a whole set of factors is taken into consideration, and each factor is taken into consideration and used as a guideline. Enterprises are divided between classical organizational structures and organic structures. With great competitiveness, unpredictable market and great globalization, new forms of organizational structures are constantly emerging in society. Contemporary shapes of structure are just the classic structural shapes applied to modern companies according to the criteria imposed by the company. The question arises: "Which organizational structure is adequate for the enterprise"? The thesis is divided into five parts. After the introductory words, the second part follows the forms of organizational affairs. The forms are divided into three types, namely: classical forms of organizational structure, organic forms of organizational structure and other forms of organizational structure in modern enterprises. After explaining the forms of organizational structures, the section of companies in the Republic of Croatia follows. Along with the initial part where companies were generally discussed in Croatia, a part was made about the types of companies and the companies themselves in the Zadar County. As a fourth part of the paper, research has been conducted. The research identified the characteristics of organizational structures on large enterprises in Zadar County. At the end of the graduate thesis, a list of literature and contributions is provided after the closing words.