The tolerance to various concentrations of sodium chloride of 10 Trichophyton sp., 6 Microsporum sp., 3 Epidermophyton sp. and 10 Candida albicans strains were studied. Candida albicans strains were found to be resistant to the sodium chloride, up to 40% at concentrations. Dermatophytes, however, did not grow at sodium chloride concentrations higher than 2.5%. These results suggest that the relative tolerance of fungi to the ionic strength can be used in diagnosis besides the other tests.