Background: Cytomegalovirus (CMV) infection remains a major cause of morbidity, mortality, and increased healthcare burden in recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Its clinical manifestations range from asymptomatic CMV replication to end-organ diseases such as pneumonia, gastroenteritis, and retinitis, all of which are associated with a higher rate of nonrelapse mortality. Methods: We reviewed case records of children who underwent allo-HSCT at our center between April 2013 and October 2024. CMV monitoring was performed weekly until at least day +100 post-HSCT using a quantitative polymerase chain reaction assay. All patients received acyclovir prophylaxis. Pre-emptive intravenous ganciclovir therapy was initiated when CMV-DNA levels exceeded 500 IU/mL Results: A total of 150 consecutive patients (58% male) were included. The median age at HSCT was 6.3 years (interquartile range [IQR], 3.4–11.3 years). Indications for HSCT were hematologic malignancy (n=81, 54.0%), inborn errors of immunity and bone marrow failure (n=46, 30.7%), and hemoglobinopathy (n=23, 15.3%). Donor and recipient CMV seropositivity rates were 86.7% and 94.0%, respectively. CMV infection occurred in 43.4% of patients, with a median onset of 30 days post-HSCT (IQR, 21–47 days). There were five (3.3%) cases of CMV disease, resulting in one (0.7%) CMV-related death. Human leukocyte antigen (HLA)-haploidentical donor status (odds ratio [OR], 5.00; 95% confidence interval [CI], 2.43–10.29; P<0.001) and the use of serotherapy in the conditioning regimen (OR, 2.87; 95% CI, 1.47–5.60; P=0.002) were significantly associated with an increased risk of CMV infection. Conclusions CMV infection was a common occurrence, particularly among patients with HLA-haploidentical donors. Preventive strategies such as weekly surveillance and pre-emptive ganciclovir therapy proved effective in preventing overt CMV disease.