This article explores the factors that contribute to the success or failure of gender quota campaigns through an analysis of two case studies from the Pacific Islands region: Samoa and Papua New Guinea. While Samoa became the first Pacific independent state to implement a parliamentary gender quota in 2013, a campaign for 22 reserved seats in the Papua New Guinea Parliament before the 2012 general election was unsuccessful. Drawing on media analysis and interviews with key players in the gender quota debates in both countries, this article examines why the push for a quota succeeded in Samoa and not in Papua New Guinea. The local, external and structural factors commonly found in gender quota literature can help to explain the divergent outcomes of the gender quota campaigns in these two countries. In particular, I highlight one structural factor – political stability – as fundamental to our understanding of the different outcomes in the two cases.