A new species of Rhipsalis (Cactaceae) from Rio de Janeiro State, in southwestern Brazil, is described and illustrated. The new Rhipsalis aurea is circumscribed in the subgenus Erythrorhipsalis and is morphologically most similar to R. pulchra Loefgr., but is distinct by the smaller, suberect habit, smaller secondary stem segments of determinate growth, golden yellow flowers, depressed-globose fruit, and epidermis and pollen grain features. Following the IUCN criteria this new species is vulnerable due to its restricted area of occurrence and reduction of the quality of habitat observed in the present and projected for the future. A taxonomic key to the subgenus Erythrorhipsalis is included.