Increased resistance of strains to antifungal drugs has gained increasing attention. We studied the status of fungal isolation from blood and vascular catheters at Juntendo University Hospital from 1994 to 2002. The major fungi isolated were Candida albicans, Candida parapsilosis, Candida glabrata and Candida trophicalis, or 86% yeast-like fungi. Isolation of these fungi from vascular catheters is increasing. The effectiveness of 6 anti-fungal agents against 116 yeast-like fungi was measured by microdilution. In antifungal activity of micafungin (MCFG), MIC90, was < or = 0.03 g/mL for C. albicans, C. glabrata and C. tropicalis. MCFG showed the strongest antifungal activity among the drugs tested for above Candida spp.. Five of 37 strains of C. albicans were resistant to fluconazole (FLCZ) showing MIC > or =64 g/mL. These strains were also resistant to itraconazole (ITCZ) but MICs of MGFG, flurocytosine (5-FC) and amphotericin B (AMPH-B). Two of 38 strains of C. parapsilosis are resistant to flurocytosine (5-FC) showing MIC > or =64 g/mL. There is no resistant strain of fungi (yeast-like organisms) tested against AMPH-B. Six patients from whom resistant fungi were isolated from blood and vascular catheters have severe diseases and/or are have just undergone a major surgical operation. These results indicate that it is vital for deep mycosis to start early treatment with appropriate drugs selected based on rapid detection and identification of organisms and the drug susceptibility of organisms.