Queensland is different from other states in that it only has a lower house. In other states minor parties achieve representation in upper houses — and therefore have a role in government — through proportional representation voting systems. Nevertheless, a vote for a minor party in Queensland can still be important because of the state’s optional preferential voting system. Where a candidate does not achieve 50% of the primary vote in an electorate, preferences are distributed to decide the winner. In this weekend’s election, preferences for the Green Party and Katter’s Australian Party will likely be crucial in deciding the outcome in some seats. In Queensland there has been a public spotlight on issues of coal seam gas (CSG), coastal development and health of the Great Barrier Reef. Many voters are likely to attach importance to one or all of these issues. This article reviews the issues, compares party policies and suggests voting options.