Perenniporiella chaquenia sp. nov. is described from Argentina. New records of P. pendula and P. micropora are discussed. A key to Perenniporiella species is presented. Preliminary phylogenetic relationships of Perenniporiella are inferred from parsimony and Bayesian analysis of a combined set of DNA sequence data (nuclear ribosomal partial LSU and ITS). It demonstrated that Perenniporiella forms a well resolved monophyletic clade distantly related to Perenniporia s.s. It also clearly showed that within Perenniporia as usually conceived other morphologically homogeneous group of taxa, such as the P. ochroleuca or P. vicina alliances, form well resolved clades, which could be recognized as distinct genera. The differentiation of the hyphal system and the basidiospores morphology are outlined as critical features for the definition of genera in the Perenniporia complex.