ABSTRACT: Cytomegalovirus (CMV) results in significant morbidity and mortality following hematopoietic cell transplantation (HCT). Establishing the cost and clinical impact is imperative to the selection of appropriate CMV preventative strategies. This is a retrospective cohort study of consecutive patients undergoing their first allogeneic HCT between January 1, 2009, and December 31, 2013. Detailed clinical and institutional cost data were obtained from the start of conditioning through 1-year post-transplantation. Baseline characteristics, resource utilization, costs, and outcomes were compared between patients with and without clinically significant CMV infection (csCMVi). One hundred seventy out of 388 patients (44%) developed csCMVi within 1 year after HCT. Within the first year post-HCT, patients with csCMVi had a significantly longer transplantation-related length of stay (mean, 91.7 days versus 78.3 days; P < .0001) and more frequent and prolonged hospitalizations (mean, 2.4 versus 1.7 admissions [P < .0001]; mean, 39.1 versus 31.5 inpatient days [P = .001]) without significantly more admissions to the intensive care unit (28.2% versus 21.6%; P = .408). The use of granulocyte colony-stimulating factor was greater in patients with csCMVi (73.5% versus 54.1%; P = .0001), although no significant differences were demonstrated in mean platelet or red blood cell (RBC) transfusions. Total costs were also higher in patients with csCMVi (mean cost difference, $45,811; 95% CI, $26,385 to $67,544). However, the incidence of graft-versus-host disease (GVHD) and selected infectious complications was not significantly different between the 2 groups. There were no significant differences in 1-year and 5-year post-transplantation overall survival (OS) or nonrelapse mortality (NRM) between those with and those without csCMVi, although relapse of underlying disease was significantly lower in the csCMVi group. Overall, our data show that allogeneic HCT recipients with csCMVi had significantly greater medical resource utilization and costs than those without csCMVi. However, clinical outcomes, including GVHD, infections, and mortality, were similar in the 2 groups. Further study is needed to determine the cost-effectiveness of CMV preventive modalities.