This chapter describes the maturation of comparative political communications as a sub-discipline and defines its conceptual core. It then lays out the concept of “political communication system”. At the macro-level, this model captures the patterns of interaction between media and politics as social systems; at the micro-level it captures the interactions between media and political actors as individuals or organizations. Comparative research in this tradition focuses on the structure of political communication systems, its culture, the construction and dissemination of messages, and the effects of those messages. A wealth of empirical studies is systematized according to the dimensions of this heuristic and evaluated in terms of their contribution to a better overall understanding of comparative political communication.