Minimal inhibitory concentrations (MICs) of Ro 14-4767/002 for pathogenic yeasts, Aspergillus spp., dermatophytes and other filamentous fungi were determined in dilution tests under a variety of experimental conditions and, for the most of the species and a number of different isolates. Ro 14-4767/002 showed the highest effect against dermatophytes and Cryptococcus neoformans, followed by Candida spp., whereas its activity against Aspergillus spp. was weak. Its activity against most pathogens compared favourably with antifungals of the imidazole class. The activity of Ro 14-4767/002 not only differed between the species but there was also a significant intra-species variation. The MICs were influenced by the inoculum size, the incubation time, and by the composition of the medium. The activity of the compound was significantly higher on Casitone agar than on a chemically defined medium (Yeast Nitrogen Base + glucose). Ro 14-4767/002 was also found to exert fungicidal activity which was time- and concentration-dependent.