Although the overall incidence of fungal infections in liver transplant recipients has declined, these infections still contribute significantly to the morbidity and mortality of patients with risk factors for infection. Although antifungal prophylaxis has been widely studied and practiced, no consensus exists on which patients should receive prophylaxis, with which agent, and for what duration. Numerous studies have attempted to ascertain independent risk factors for invasive fungal infections in liver transplant patients, and these data, in addition to clinical trials, identify several patient groups at exceedingly high risk of fungal infection. These include retransplant patients, patients with renal failure requiring hemodialysis or renal replacement therapy, and those requiring reoperations after transplant. Because the majority of infections occur in the first month after transplantation, prophylaxis should be continued for 4-6 weeks. However, local epidemiology and research should guide decisions regarding choice of agent as well as overall development of interinstitutional guidelines, because the incidence and spectrum of infection may differ dramatically among institutions. Fungal infections are one of the most devastating infectious complications of liver transplantation, contributing significantly to both morbidity and mortality in these patients. 1 Management of invasive mycoses, particularly Aspergillus infections, has proven remarkably challenging. Of the 5%-40% of liver transplant patients who develop an invasive fungal infection (IFI), 2-4 mortality associated with these infections ranges from 25%-67%, 5 although Aspergillus-associated mortality is as high as 60%-90%. 4,6,7 A variety of factors, including environmental exposures, technical/anatomic issues, and the degree of immunosuppression present interact in the causation of fungal infection. 8 An understanding of these interactions and effects is vital for the assessment of risk for serious fungal infections after transplantation and the development of prophylactic strategies.