Despite advances in surveillance strategies and antivirals, cytomegalovirus (CMV) infection continues to pose problems to patients receiving hematopoietic stem cell transplants (HSCTs). The bone marrow transplant (BMT) unit at the Singapore General Hospital embraced the preemptive strategy in late 2003. Although several studies have demonstrated its usefulness, we conducted this review to document CMV-related events at our institution. Forty-six patients underwent CMV surveillance using the CMV pp65 antigenemia (CMV Ag) assay from January 2004 to December 2005. Twenty-seven patients had CMV infection, and 19 remained antigenemia-negative. No differences were found between the 2 groups for the following potential risk factors for CMV infection: age, total number of co-morbidities, duration of neutropenia after conditioning, baseline creatinine, type of conditioning regimen (conventional vs. reduced intensity), type of transplant (matched sibling vs. others), recipient CMV status, donor CMV status, and use of total body irradiation. Two patients received alemtuzumab; both developed CMV Ag. Twelve episodes of CMV infection occurred after the 100th post-HSCT day. Two patients developed CMV disease. One of them could be considered a failure of the preemptive strategy, as she had CMV gastritis diagnosed on the same day that she became pp65-positive. The other developed CMV disease despite prompt institution of ganciclovir, although she had multiple post-HSCT complications requiring enhanced immunosuppression, as well as relapsed disease. One-year disease-free survival was 55.5% in those with CMV infection and 52.3% in those without infection. Survival was not affected by CMV infection.