Three cultivated strains of homothallic mushroom Volvariella volvacea and one cultivated strain of V. bombycina were differentiated by DNA fingerprinting techniques, restriction fragment length polymorphisms (RFLPs) and arbitrarily-primed polymerase chain reaction (AP-PCR). Three multilocus RFLP markers were randomly labelled with digoxigenin-dUTP during PCR and southern hybridized at high stringency with the partially digested DNA mixtures. In two RFLP markers, V. bombycina did not cross-hybridize in contrast to the amplification of all DNA samples in 3 primer reactions of AP-PCR. In both techniques, V. bombycina showed distinct DNA fingerprints but the V. volvacea strains had to be differentiated using more than one marker/primer. In comparison, AP-PCR is a simple method to generate DNA fingerprints and to differentiate species and strains. Also, the observed highly similar DNA fingerprints may reflect the lack of heterogeneity in commercial V. volvacea strains.