A taxonomical review of the Hydrocotyle L. (Araliaceae), species native to the Siberia cloud forest, Parque Nacional Amboró (Bolivia), is presented. Six species are known from this zone, four of which are described as new: H. adrianae M. Mend., H. felipae M. Mend., H. juanae M. Mend., and H. lopeziae M. Mend, all of them presumably endemic to the region. The new species are illustrated, a key to facilitate identification is provided, taxonomical differences between related species are discussed, and notes on the ecology and natural distribution are given for each species.