Representative democracy is based on the notion that we hold elections every few years to elect politicians to make decisions on our behalf. While this is a central feature of most systems of government, there are other important links between politicians and the communities which they govern; links which have a significant impact on government decision making. We have already discussed the important role of political parties, how some parties represent certain sections of society and how this influences the way that they govern. This chapter examines an alternative avenue of representation; the way in which individuals and firms form interest groups to try to influence governments. It begins by outlining the key features of an interest group and goes on to outline some of the ways in which they can enhance democratic decision making. As with so many aspects of the political process, there are also critics of interest groups who argue that they can become too powerful and dominate governments, creating a situation that benefits a powerful elite at the expense of the general public. In order to assess such arguments, we introduce a basic system for classifying interest groups according to their membership structure and relationship with government. Having established this framework the chapter concludes with a more detailed assessment of business interest groups in Australia, how they are organised and the influence that they exert on Australian politics.