A forty-eight-year old male diagnosed with acute lymphocytic leukemia was further complicated by Candida krusei fungemia despite introduction of fluconazole prophylaxis during antileukemic therapy. The fungemia subsided after intravenous amphotericin B therapy followed by itraconazole therapy. Multiple ulcerative lesions and a carcinoid lesion were observed in the transverse colon, and it was thought that the C. krusei had invaded from the ulcerative lesions. Azole antifungal agents, especially fluconazole, have frequently been used for therapy and the prophylaxis of fungal infections. Though infections due to fluconazole-resistant Candida species such as C. krusei are a growing problem, in the hematology division of our hospital there is no evidence of an increasing incidence of C. krusei fungemia or an increasing rate of C. krusei in surveillance culture from admitted patients. However, future increases in infections due to fluconazole-resistant Candida species like C. krusei and C. glabrata are entirely possible, making it necessary to identify isolated fungi, perform susceptibility tests on antifungal agents against isolates, measure the serum concentrations of antifungal agents, and then to treat patients with the appropriate therapies.