The spectrum of infections in transplant recipients has been substantially affected by novel immunosuppressive regimens and the use of antimicrobial agents. Epidemiology and presentation of traditional opportunistic pathogens has changed. Invasive aspergillosis and cytomegalovirus occur later in the post-transplant period. The incidence of infections that were previously encountered rarely--eg, BK virus nephropathy--has increased, the clinical course of hepatitis C virus recurrence has become more aggressive, the risk factors for invasive aspergillosis have changed, and non-aspergillus moulds are occurring more commonly in transplant recipients. Recognition of these trends as they unfold has significant implications for the clinical care of the transplant recipients, for providing insights into the pathogenesis, and for continually improving the approaches to the management of infections.