The aim of this study is to present the personality traits, types of leadership in the organization and the relationship between the "Big five" model of personality and types of leadership. The development of personality traits throughout history is presented. Approaches of personality are also presented and can be separated into psychoanalytic, behavioral, cognitive, humanistic and evolutionary approach. This study emphasizes the "Big Five" model of personality traits that is divided into: neuroticism, extraversion, openness to experience, agreeableness and conscientiousness. Furthermore, certain types of leadership in the organization are presented and classified into broader approaches: personal, behavioral, and contingency approach. Also, contemporary leadership styles are briefly described. The principles of leadership and the characteristics of the leader are stated, also as the characteristics of a successful leader, as well as the types of organizational power. The greatest attention in this study is on the three basic leadership styles: autocratic, democratic and laissez - faire. This study connects leader’s personality traits with the types of leadership in the organization, while it emphasizes the relationship of "Big Five" model with three basic types of leadership: autocratic, democratic and laissez-faire. Since it is necessary to link theoretical findings to the practical example, the Antiterrorist Unit Lučko was analyzed in empirical part of this study. The managerial functions in the Antiterrorist Unit Lučko are specifically divided and each level is analyzed individually. Managers at each level were enabled to fill in the Big Five Inventory while the results show which personality traits are highlighted in each of the managers. The results are related to the type of leadership that managers in the organization use the most and how employees respond to the requests of individual manager.