In this study, the attitude of the European Union towards the Principle of Subsidiarity and the way it utilizes this principle is analyzed. Besides putting forward the fundamental principles of subsidiarity within the historical framework that it has evolved through, the factors that made the Union adopt subsidiarity and the attitude of the Community institutions towards this principle are examined. In this regard, the role that the principle of subsidiarity has played in the European integration process so far and those that it may play in the future formation of the Union is discussed.