BACKGROUND: Although heart transplantation is the only therapeutic modality for patients with end-stage heart disease, immunosuppressive therapy to reduce organ rejection may increase the risk of infection in transplant patients. Little is known regarding infectious complications in heart transplant recipients in Korea. Thus, this study was performed to evaluate the clinical features and outcome of infectious complications in patients receiving heart transplantation. MATERIALS AND METHODS: A retrospective cohort study was performed by reviewing medical records of patients who underwent heart transplantation from December 1996 to October 2008 in Samsung Medical Center, Seoul, Korea. RESULTS: A total of 72 cardiac allograft recipients were included in the analysis. Median follow-up duration was 417 (range, 2-3995) days. During the follow-up period, 75 infectious complications occurred in 39 (54.2%) recipients, of which 31 cases (41.3%) were caused by bacteria, 28 (37.3%) by viruses, 10 (13.3%) by fungi, 4 (5.4%) by Pneumocystis jirovecii, and 2 (2.7%) by Mycobacterium tuberculosis. Median onset time of bacterial, viral and fungal infection were 153, 106 and 68 days, respectively. The most common site of infection was lung (n=26, 34.7%), followed by gastrointestinal tract (n=11, 14.7%) and oral cavity (n=9, 12%). All patients were sero-positive for cytomegalovirus (CMV)-specific IgG before transplantation and received preemptive therapy of CMV infection. After heart transplantation, 44 (63.8%) patients experienced CMV reactivation identified by CMV antigenemia and 9 (13%) patients had organ-specific CMV diseases. The overall mortality rate was 33.3% (24/72). Infectious complications were the most common cause of death (n=10, 41.7%). The operative risk factors for death were lung infection, fungal infection and bloodstream infection. CONCLUSIONS: In the current study, the lung was the most common site of infection and bacteria were the most frequent etiologic pathogens among heart transplant recipients. Infectious complications, especially fungal infections were the most common causes of death. Prevention strategies against fungal infections should be evaluated in the future studies.