Protoanemonin, a component of Ranunculus bulbosus, was tested as an antifungal agent on selected strains of dermatophytes and yeasts. The minimum inhibitory concentrations ranged from 2.0 to 7.5 X 10(-4) M and the minimum lethal concentrations from 3.8 X 10(-4) M to greater than 1.0 X 10(-3) M. The