The pathogenicity of three cultures isolated as Phialophora jeanselmei was compared with that of three cultures of Phialophora gougerotii using ddY mice. One hundred and twenty mice were used. They were divided into 6 groups consisting of 20 each. Each culture was evaluated in 20 mice. Mice were inoculated intravenously with 0.2 ml of a 1% (wet weight/vol.) yeast-like cell suspension and sacrificed at adequate intervals until the 30th day. As results, 1) the virulence of the three cultures each of P. jeanselmei and P. gougerotii to ddY mice was mild. 2) These cultures were not neurotropic. 3) P. gougerotii survived longer in the mice than P. jeanselmei. 4) There were no major differences in histopathology of the lesions in the mice inoculated with the two taxa.