The genus Pseudognaphalium is one of the largest genera of the tribe Gnaphalieae (Asteraceae) with about 90 species with worldwide distribution. The vast majority of species are found in South, Central and North America, but some species also occur in Asia and Africa. This work includes the revision of 12 species of Pseudognaphalium from Chile, P. aldunateoides, P. cabrerae, P. cheiranthifolium, P. cymatoides, P. gayanum, P. lacteum, P. landbeckii, P. munoziae, P. psilophyllum, P. remyanum, P. tarapacanum, and P. viravira. A key is provided for their identification, as well as morphological description, illustration, geographic distribution and habitat, distribution maps, phenology, additional material examined, distinguishing characters and taxonomic affinities for each taxon. The new combination Pseudognaphalium cabrerae (S.E. Freire) S.E. Freire, N. Bayón, C. Baeza, Giuliano & C. Monti, is proposed. The following taxa are newly synonymized: Gnaphalium diminutivum, Pseudognaphalium perpusillum, with P. aldunateoides; G. canum, G. ulophyllum, P. moelleri with P. cymatoides; P. heterophyllum, P. heterotrichum, G. pseudohelichrysum, P. robustum with P. gayanum; P. glandulosum with P. psilophyllum; G. longifolium, G. subnudum, P. andicola, P. coquimbense, P. illapelinum, P. montevidense, P. pratense, with P. viravira.
