Leadership is one of the basic functions of management. The leader can achive his influence through numerous ways, ranging from complete autocracy to complete tolerance. Based on this, the different systems of management are being formed, which establish different styles of leadership. Many theorists point out a significant impact of leadership and management models to organization success. Rensis Likert developed one of the most famous behavioral models in 1961. The main findings of his research can be summarized in two conclusions. One shows that the management is the cause, and not a result of the productivity of the organization, which is supported by the fact that the change of leadership leads to changes in the productivity of enterprises. The second conclusion points out that there are important differences between successful and unsuccessful leaders or organizations they manage. The most obvious differences are in orientation, relationships, communication, methods of control and principles of management. Based on the results obtained in his research, R. Likert developed a model with four management systems: exploitative-authoritative, benevolent-authoritative, consultative and participatory. A research of interdependence of managers leadership styles and the size of banks in the banking sector of Republic of Croatia in which managers were employed, was conducted based on this model. Results showed all banks in Republic of Croatia, regardless of size, cherish consultative style.