The main theme we want to adress in this thesis is the way the Second Vatican Council recognizes the role and the mission of a bishop of the Church. This topic is actual in various theological sub-disciplines, but we will adress it mainly form the ecclesiological aspect, while also taking into account other theological aspects. The basis of this thesis are the two of the council documents that sistematically approach the role and the mission of the bishops of the Church. Those documents are the Dogmatic Constitution on the Church – Lumen Gentium, and the Decree on the Pastoral Office of Bishops in the Church – Christus Dominus. The thesis is divided into seven chapters, and it begins with biblical approach and biblical fundamentals of the office of a bishop, so as with the role it had in the first christian communities. The second chapter adresses the development of ecclesiology with regards to the office of a bishop, beginning from the apostolic and the fathers of the church who established it, through medieval theology, all the way to the theological thoughts of the council fathers of the First Vatican Council. This type of approach gave the needed introduction of the following chapters that deal sistematically with the office of a bishop in the way the Second Vatican Council understands it. The third chapter brings the new views of the Second Vatican Council, while the fourth chapter elaborates the Second Vatican Council's teaching on the consecration of a bishop. The fifth chapter analyses the relation of a bishop to his local Church, and in that respect brings the Second Vatican Council's interpretation of his triple role in the Church. After the exposition of the role a bishop has in his local Church, the sixth and seventh chapter explain the bishop's role in the universal Church. Therefore, this thesis also deals with the College of Bishops of the Catholic Church and in the end with the Synod of Bishops in the Catholic Church. This concludes the thesis.