What role and influence have developing countries during the negotiations of international environmental agreements? This broad topic is analysed through the case study of the recognition of Farmers’ Rights in the International treaty on plant genetic resources for food and agriculture (ITPGRFA), adopted by the UN Food and Agriculture Organisation (FAO) in 2001. Farmers’ Rights became part of the political debates regarding international management of plant genetic resources for food and agriculture (PGRFA) during the 1980s. Countries of the South were provoked by the fact that modern plant varieties in the North got protected by plant breeders’ rights, while their traditional varieties were considered as common heritage of mankind. Thus, the concept of Farmers’ Rights was presented as a counterpart to plant breeders’ rights in order to recognise the breeding of traditional farmers mainly in the South, but also as a mean to support their conservation efforts of PGRFA.        By comparing the developing countries’ original proposal on Farmers’ Rights and the outcome of the negotiations (the text of the treaty), I conclude that the developing countries had a medium breakthrough for their interests. I use regime theory in order to understand this outcome. Not surprisingly, the interest-based perspective has high explanatory power. The way of organising the negotiations as well as entrepreneurial leadership conducted by diverse actors affected the possibility for developing countries to get their interests attended to. Their issue-specific power however, has been reduced due to their decreasing control over PGRFA since much PGRFA by now is collected in international genebanks and during the seven years of negotiations, different groups of developing countries developed different interests and strategies. The knowledge-based perspective highlights the role of nongovernmental actors such as epistemic communities and NGOs, that to a large extend supported developing countries’ demand for Farmers’ Rights. The powerbased perspective has less explanatory power when the ITPGRFA is studied in isolation. By looking at other agreements of relevance for Farmers’ Rights, including the Agreement on Trade-related Intellectual Property Rights (TRIPs) and the International Convention on the Protection of New Plant Varieties (UPOV), the dominance of the materially strong states become more apparent.