BACKGROUND: The purpose of this paper is to present the finding of Suaeda foliosa in El Yali National Reserve, Chile. With this finding, the southern limit of the distribution is displaced from the current position at 31° S, 300 km southward. FINDINGS: In this work, we found this species on the banks of the Colejuda lagoon, 33° 45' S, which belongs to a body of hypersaline seasonal water found inside the protected area distinguished as a Ramsar site (No. 878). The determination of the genus and species was achieved by comparing with herbarium material deposited in the National Herbarium SGO Natural History Museum in Santiago de Chile. Once we identified the species, the collected material was deposited in the referred Herbarium (SGO 163975). pH, salinity, and conductivity of the water column and soil adjacent the three protected lagoons are compared, discussing the unique conditions of the lagoon Colejuda that may explain the presence of S. foliosa only in their environment and not in other water bodies. CONCLUSIONS: It can be concluded that El Yali wetland system harbors the S. foliosa southernmost population of the Americas.