In the Montane areas of Cordillera, the Philippines, the IP (indigenous people) have cultivated native rice for generations on their rice terraces, which were designated a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Cultural Heritage site in 1995 and a Food and Agriculture Organization (FAO) World Agricultural Heritage site, Globally Important Agricultural Heritage System (GIAHS) in 2011. This heirloom rice was registered as a collective trademark in 2018 and will be registered as a sui generis geographical indication (GI) in the coming years. Based on the author’s interviews with the stakeholders in heirloom rice production conducted in the Philippines in 2019, this article aims to analyze whether GI and patrimonization contribute to the sustainability of the IP communities in Cordillera. This paper demonstrates that GI and patrimonization exhibit both potential and contradictions in ecological, socio-cultural, and economic dimensions of sustainability in the communities, and the compatibility of these dimensions is challenged. The paper concludes that public policies need to pay particular attention to accompanying IP communities when GI and patrimonization are designed to protect them from over-development of the designated area and over-commodification of their certified agri-food products.