The basis of business success of each company is a well-defined organizational structure. It helps to achieve the given goals and to conduct certain strategies. Choosing a form of organizational structure is a decision of strategic importance for each company. There in no business organization with the same organizational structure, and it can't be the same at different stages of company development. Different forms of organizational structure show different ways of grouping jobs, conducting internal division of labor and forming organizational units at all levels of the organization. Once the organizational structure is defined, the job is not completed, depending on various factors of influence, it is changing, supplementing and improving. The organizational structure of a bank also depends of many factors, the market in which bank wants to position itself, the bank's strategy, and the laws and regulations. Hrvatska poštanska banka d.d. is organized through 21 organizational units, 12 offices and 9 sectors, which are grouped into four functional areas in order to manage and organize the Bank's operations more effectively. Hrvatska poštanska banka d.d. it continuously improves its business and bases its development direction on growing market share.