For many countries, despite their adoption of quotas, women's political participation remains low. Costa Rica, however, presents a success story in terms of increasing women's descriptive representation and, as a country which has tried a variety of quota systems, it represents a unique case study. This article looks at the processes which have influenced the evolution of the Costa Rican experience, and the struggle to achieve effective quota law highlights the importance of clear, unambiguous legislation that leaves no loopholes for those resisting its implementation. However, there is also a cautionary note that although quotas can be effective in increasing numbers, the quest by women's organisations to seek transformation can be co-opted by others leading perhaps to undesired outcomes. The quota system can ensure a higher presence of women but it does not necessarily enhance democracy or social justice, or promote women's interests within the public agenda.