Three new species of Corethromyces (Ascomycetes, Laboulbeniales, Stigmatomycetinae) parasitic on South American Staphylinidae (Insecta Coleoptera) are described. These are C. aequatorialis, parasitic on Gnathymenus sp. from Ecuador, C. otongaensis, parasitic on Biocrypta sp. from Ecuador, and C. thayerae, parasitic on Medon obscuriventer from Chile.