The objective of this thesis work is to touch upon different aspects of this acute problem, namely to find out more about the term itself and introduce its basic concepts, outline its emergence and historical background, trace the main routes and destinations of the outflow. With the help of available data its estimated magnitude will be presented and possible reasons with consideration of "push" and "pull" factors behind this universal phenomenon revealed. Some far-reaching effects of brain drain and their importance in terms of economic and social development will also be examined.