The aim was to evaluate the in vitro activity of voriconazole compared with those of amphotericin B, itraconazole and fluconazole against 132 bloodstream isolates of Candida non-albicans and Saccharomyces cerevisiae species. The minimal inhibitory concentrations (MICs) were determined by an adapted National Committee for Clinical Laboratory Standards (NCCLS) M27-A method using RPMI 1640 as test medium supplemented with 2% glucose. MIC end-points were determined with a spectrophotometer after incubation for 48 h at 35 degrees C. Optical density data were used for the calculation of the MIC end-points. For amphotericin B, the end-point was defined as the minimal antifungal concentration that exerts 90% inhibition compared with the control well growth. For the azoles, the end-points were determined at 50% inhibition of growth. Amphotericin B is highly active with 97% of isolates inhibited by < or =1 microg ml(-1). Decreased susceptibility or resistance to fluconazole was the rule among C. krusei, which is intrinsically resistant to fluconazole. For C. glabrata isolates, resistance to fluconazole and itraconazole was measured in 13% and 17% of the isolates respectively. Voriconazole was quite active in vitro against all the isolates with a MIC90% of < or =1 microg ml(-1) and we conclude that it may be useful in the treatment of non-albicans bloodstream infections.