: Traditional studies on political consequences of electoral systems were recognising electoral formula as the most important variable responsible for the consequences generated by a given electoral system. Meanwhile, recent studies suggest that the impact of this variable is defi nitely overrated. The article shows how the number of seats won in electoral districts affects the political parties and their candidates' chances of winning both in the proportional representation voting systems as well as in the majority and plurality ones. Using the examples of Polish parliamentary elections, the present paper both examines the thesis according to which larger electoral districts always increase proportionality and identifi es the conditions under which the thesis finds its application.