Solid organ transplantation has been established as an accepted treatment modality for end-stage diseases. Although the prognosis for organ recipients has improved with the development of surgical technical skills and the application of newly developed immunosuppressive agents, opportunistic infections remain the major cause of death in these patients. Invasive aspergillosis is one of the most common fungal infections in solid organ transplantation, and it carries a high mortality rate. In Korea, eight sporadic cases of invasive aspergillosis after kidney or heart transplantation have been reported. Recently, we experienced five cases of invasive aspergillosis after liver or heart transplantation over a four year period. Among these five patients, three died of uncontrollable aspergillosis and one died of heart failure and graft rejection. Early diagnosis and treatment are essential for the improvement of the prognosis for invasive aspergillosis after solid organ transplantation.