A long tradition within political science examines the impact of party canvassing on voter participation. Very little of this work, however, is comparative in scope. This essay examines how system-level characteristics shape the nature and impact of party canvassing and how voters respond to those efforts. Parties are found to target the same types of potential voters everywhere -those who are likely to participate. However, one important difference is that overall levels of party contact are far greater in candidate-based systems than in proportional representation (PR) systems. Party mobilization, therefore, cannot explain the higher rates of turnout observed in PR systems.A long tradition within political science has identified the importance of party mobilization efforts to voter turnout. Such work, which has often employed an experimental approach, has tended to focus on the impact of campaign work, on voter willingness to turn out and on the importance of various means of contact -mail, telephone or doorstep -upon voters. 1 Typically these studies have been made within the context of a single country, usually that of Britain or the United States. 2 In this article we move beyond a single system to compare mobilization across seven different countries with different electoral systems in order to ask questions about the level and kind of mobilization efforts that take place. The broader theoretical relevance of this work lies in its extension of the literature on electoral systems. Within this literature, considerable bodies of work discuss comparative features of party life such as policy positioning or candidate nomination. 3 Here we extend a discussion of cross-system effects to consider how these system-level characteristics shape efforts to 'get out the vote' and, also, voter responses to those efforts.