Experimental central nervous system (CNS) phaeohyphomycosis was established in cortisone-treated mice following intranasal exposure to conidia of Xylohypha bantiana (Cladosporium bantianum, C. trichoides). X. bantiana was recovered from the lungs of 78% of intranasally inoculated normal mice sacrificed within the first 3 days of infection and from 15% at day 28. The fungus was not recovered from the brains of normal mice. In contrast, X. bantiana was recovered from only 33% of the lungs of cortisone-treated mice within the first 3 days of infection. However, the fungus was recovered from the brain of 11% of cortisone-treated mice sacrificed or dying over a 28 day period. Histologically and temporally the CNS disease in cortisone-treated, intranasally inoculated mice was consistent with hematogenous dissemination from a primary pulmonary focus.