Many studies and dissertations have been written on the questions where organized crime was started, what it means, and how and into what it has evolved. Just as much has been already dealt with the question how the law enforcement agencies have evolved, what typical stages have appeared during their operation. However, it is less clear how these two things interact or were interrelated, and more specifically, how organized crime and its development on has impacted law enforcement agencies, what organizational changes have been generated by a particular crime or a new offense method. In this dissertation, after defining the concept and characteristics of the organized crime, this time I would like to present the events and circumstances that determined its development and changes in Hungary, as well as what temporary or permanent organizations were fighting against these phenomena. Finally, besides the organizational effects, I present the training opportunities that contributed to the effectiveness of law enforcement.