The term of leader is used increasingly frequently in various works. Although the concept of leader appears with the organization of society and manifestation of the phenomenon of power, currently there is no unique definition of leader. Finally, all definitions of the leader were reduced to a series of five categories: first category includes definitions of the leaders which categorized them as people entrusted with power by the appointment or election to the default organizational structures; the second category deals with the leader like a “central person” in the group; the third category present leaders as favorite or popular persons; the fourth category considers the leader as the most competent person in the group; the fifth category defines the leader as a member of a group which exercises an accepted influence on the overall group or person who exercises the largest influence in the group. Referring to the theories of leadership, we must note that in the literature have outlined several theories and approaches in this regard. In a broader approach, theories of leadership can be conventionally classified into the following categories: personality theory (qualitative approach, biological approach, psychoanalytic and etiological approach); situational theory of leader, that consider the leader as a product of a situation that possess certain qualities; constituents theory - this approach assumes that the leader acts on behalf of their group and reflects aims of the group; interaction theory which treat the leader as a product of interaction of several factors. A synthesis of theories reflected in scientific literature allows to highlight the following theories: personalities theories, behavioral theories, primary situational theories, contingency theories, cognitive theories, theories of social interaction. It would be incorrect to equate the way how the types of leaders are described theoretically and their practical expressing. Also it would be incorrect to say that some of them can be considered effective and others less efficient. For an effective leadership, a dynamic and flexible leader must adhere to the majority of management styles (depending on environment).