Phenotypic and genotypic features of three teleomorphic species, Petromyces alliaceus, P. albertensis and P. muricartus and some related anamorphic Aspergillus species were compared. The dendrogram based on carbon source utilisation data revealed a close relationship between P. muricarus and the A. ochraceus strains examined. P. alliaceus and P. albertensis strains were very closely related to each other. A dendrogram with similar topology was obtained by analysing sequences of the intergenic transcribed spacer regions of representatives of these species. P. alliaceus and P. albertensis strains could only be distinguished by the random amplified polymorphic DNA technique. These strains possibly represent a single species closely related to Aspergillus section Flavi, while the anamorph of P. turicatus is a member of Aspergillus section Circumdati. Our results indicate that Aspergillus section Circumdati is in need of taxonomic revision.