The electoral role of populist politics in Australia and New Zealand is explored within the larger context of minor party protest voting. Survey data from recent national elections used to analyse the bases of support for the One Nation Party and New Zealand First. We find that the populist parties played two fundamentally distinct roles-tapping virtually exclusive support for extremist issue-stances such as opposition to immigration and aid for indigenous minorities, while sharing their vote gain from economic concerns and political disaffection. Both roles are constrained by the countries' system of partisan competition-One Nation more likely to attract exclusive support than New Zealand First, given the latter's need to compete amongst many more small party alternatives. (C) 2001 Elsevier Science Ltd. All rights reserved.