In the past decade there has been a dramatic increase in the incidence of life-threatening Candida infections in patients in intensive care units (ICUs). Once considered a minor pathogen, Candida is now among the most commonly cultured pathogens in the ICU. This phenomenon is in part attributable to greater numbers of immunocompromised patients being hospitalized and the more frequent use of surgery, instrumentation, and broadspectrum antibiotics. Serious Candida infections can present as generalized sepsis, as focal involvement of virtually any organ, or as part of the syndrome of multiple system organ failure. Once established, these infections can be difficult to detect until their late stages and consequently are responsible for significant morbidity and mortality in ICU patients. For treatment to be successful it must be instituted promptly and, on occasion, empirically. As a result, new diagnostic techniques, treatments, and prophylactic strategies to minimize the occurrence of Candida infections are the subjects of ongoing research. This article is intended to provide practitioners with an understanding of why serious Candida infections are increasing, as well as information on pathogenesis, diagnosis, treatment, and some measures that can be taken to prevent such infections in critically ill patients.