BACKGROUND: Studies on cytomegalovirus (CMV) diseases in Korean hematopoietic stem cell transplant (HSCT) recipients are lacking and do not reflect the recent trends of advances and changes. Therefore, we tried to analyze the clinical features of CMV diseases in HSCT recipients over the past 10 years at a tertiary university hospital in Korea. METHODS: Retrospective review of medical records was done for all adult HSCT patients who received transplant at the Catholic HSCT Center from January 1998 to January 2008. RESULTS: Forty-four cases (2.2%) of CMV diseases were identified. CMV pneumonia was diagnosed in 17 patients, retinitis in 16 patients, enterocolitis in 7 patients, esophagitis 1 patient, gastritis in 1 patient, duodenitis in 1 patient, and hepatitis in 1 patient. The median onset of symptom was 90 days after transplantation. Late CMV diseases accounted for 47.7%. CMV related death varied from 0 to 58.8% according to the involved organ. CMV retinitis was diagnosed relatively later in the course of transplantation mostly in patients who had chronic graft versus host disease (GVHD). On the contrary, CMV enterocolitis mainly occurred in patients who suffered from acute GVHD. The overall concurrent CMV reactivation was documented to be 63.6%; the concurrent CMV reactivation was observed only in 37.5% of patients with retinitis. CONCLUSIONS: We observed some differences in the pattern of CMV disease manifestation according to the involved organ and reconfirmed the fact that CMV pneumonia is the most common and fatal disease in HSCT recipients. Additionally, CMV retinitis was not uncommon in HSCT recipients. Since specific marker does not exist in predicting retinitis, regular ocular examination should be done thoroughly, especially in patients with chronic GVHD.