Five new species of Gentianella Moench (Gentianaceae) are described from western South America. Gentianella decemnectaria J. S. Pringle, from Peru, is characterized by decumbent stems and nearly rotate corollas with 10 nectaries per corolla. Gentianella pluvialis J. S. Pringle, from Bolivia, is similar to G. florida (Griseb.) Holub, differing in its larger flowers with bright yellow corollas. Gentianella pyrostelium J. S. Pringle, from Peru, is characterized by its columnar habit and red and yellow, scarcely opening corollas. Gentianella rugicalyx J. S. Pringle, from Peru, differs from G. paludicola (Gilg) J. S. Pringle in its wider, abruptly acute calyx lobes and corolla tube that widens more gradually, and from G. persquarrosa (Reimers) J. S. Pringle in its leafier stems and glabrous corollas. Gentianella sanchezii J. S. Pringle, from Peru, is characterized by slender, clustered stems arising from a persistent rosette, pedicels mostly longer than the internodes, and widely funnelform, purplish pink corollas.