The order Cystofilobasidiales is described for teleomorphic basidiomycetous yeasts with holobasidia and teliospores. Their septa have dolipores, but lack parenthesomes. D-Glucuronate, nitrate and nitrite are assimilated and myoinositol is usually assimilated. Coenzyme Q has 8 or 10 isoprenologues. 25S and 18S rDNA sequence analysis indicates a monophyletic branch within the Tremellomycetidae of the Hymenomycetes. Cystofilobasidium is the type genus.