Centris (Paracentris) Cameron is one of the most specious and morphologically diverse subgenera of the bee genus Centris Fabricius. These two features, along with the lack of modern taxonomic revisions make this group one of the lineages with the greatest taxonomic problems within Centridini.
Partial revisions of groups of species from North and South America have been published, but none comprehensively studying all species described. In this paper are studied all species of C. (Paracentris) for the first time, providing diagnoses and redescriptions of both sexes. The following twenty one species are described as new: C. aenigmaticasp. nov., C. agyniaxsp. nov., C. arequipensissp. nov., C. aymarasp. nov., C. bagualissp. nov., C. caribensissp. nov., C. comonoxasp. nov., C. diaguitasp. nov., C. euctenodasp. nov., C. hexirrhinasp. nov., C. incasp. nov., C. mexicanoidessp. nov., C. millunisp. nov., C. multistriatasp. nov., C. niveicepssp. nov., C. rasmussenisp. nov., C. rozenisp. nov., C. sacsayhuamansp. nov., C. tayabambasp. nov., C. xenopodasp. nov., and C. yawarsp. nov., mainly from the South American Andes, including the first species recorded from the Caribbean. Centris satana Snelling is proposed as new junior synonym of C. laevibullata Snelling. In addition, the male of C. cisnerosi (Cockerell) and the female of C. euphenax Cockrell are described for the first time. An identification key, figures, maps, new distribution records, floral hosts, and an updated catalogue
for all species of the subgenus are also provided.