The microbiological, clinical, and epidemiological features of most non-Candida albicans Candida species are well known, but much less is known about species such as Candida guilliermondii, an uncommon pathogen causing a variety of deep-seated infections in immunocompromised hosts. To characterize C. guilliermondii fungemia in patients with hematological malignancies and its susceptibility to antifungal drugs, all cases of C. guilliermondii fungemia diagnosed in our department between 1983 and 2005 were retrospectively analyzed and the literature was reviewed. C. guilliermondii caused 29/243 (11.7%) candidemia episodes diagnosed during the study period. Central venous catheters were the documented sources of candidemia in 19/29 episodes (65.5%), and invasive tissue infections were documented in 2 (6.9%). In the remaining eight, the catheter was not removed and the source of the fungemia remained obscure. Seven episodes ended in death, but only one could be attributed to invasive C. guilliermondii infection. Molecular typing data reveal no evidence of common infection sources. Isolates displayed high rates of in vitro susceptibility to amphotericin B (100%), voriconazole (95%), and fluconazole (90%) and lower rates of in vitro susceptibility to flucytosine (86%), itraconazole (76%), and caspofungin (33%). Our literature review confirms that C. guilliermondii is a significantly more frequent cause of candidemia among cancer patients compared with the general hospital population. It accounted for <1% of the total number of Candida bloodstream isolates reported in the articles we reviewed, with higher rates in Europe (1.4%) and Asia (1.8%) compared with North America (0.3%).Non-Candida albicans Candida species have been recognized as emerging pathogens in cancer patients, particularly those with hematological malignancies. Not only are serious infections caused by these yeast species increasing in frequency, but in a number of cases the strains responsible for the infection display tolerance or resistance to antimycotics (13,41,67). The microbiological, clinical, and epidemiological features of Candida parapsilosis, Candida tropicalis, Candida krusei, and Candida glabrata are well known, but much less is known about other non-C. albicans Candida species. The few reports in the literature on Candida guilliermondii infections suggest that they are associated with poor clinical outcomes. This species has caused a variety of deep-seated infections in immunocompromised hosts and, less frequently, intravenous drug users. Like Candida lusitaniae, it is one of the fungal pathogens most likely to display in vitro resistance to amphotericin B and fluconazole (8,19,20,28,33,49,60,63,68). The present study was an attempt to learn more about the clinical characteristics of infections caused by C. guilliermondii and its antifungal susceptibility pattern. All cases of candidemia diagnosed in our department over the past 22 years were retrospectively analyzed to identify the prevalence and clinical features of C. guilliermondii fun...