OBJECTIVES: Following solid organ transplantation (SOT) or hematopoietic stem cell transplantation (HSCT), patients are at risk of cytomegalovirus (CMV) disease. The impact of CMV disease on mortality and hospitalisation costs following transplantation and on the probability of transplant rejection following SOT was estimated. METHODS: We conducted a retrospective cohort study of a database of hospitalisations in France (PMSI). Available data included demographics, hospital characteristics, diagnoses, healthcare procedures, length of stay, discharge status and costs. Logistic regression was used to estimate the impact of CMV disease during initial hospitalisation on the probability of graft rejection and mortality during initial stay or following readmission. The impact of CMV disease on costs was estimated using generalised linear modelling. All estimates were adjusted on age, gender and transplant type. A first analysis based on hospitalisation records from 2007 was performed; additional analyses accounting for patient censoring, with the data from 2008 to 2011, are planned. RESULTS: Among 4,078 SOT recipients and 3,530 HSCT recipients, CMV disease was reported during initial stay in 65 (1.59%) and 67 (1.90%) patients respectively. Case fatality rates were 5.37% and 3.23% in the SOT and HSCT recipients. CMV disease was associated with an increased mortality following HSCT (odds ratio = 3.614, p=0.0018), but not following SOT (OR=1.087, p=0.83). Graft rejection was recorded for 11.53% of SOT recipients and the odds ratio of rejection associated with CMV was 2.71 (p=0.0007). Average hospitalisation costs were €45,700 for HSCT and €32,200 for SOT. CMV disease was associated with increases in costs by 90.37% (p<0.0001) for HSCT and 86.14%  (p<0.0001) for SOT. CONCLUSIONS: CMV disease is associated with substantial increases in probability of graft rejection, mortality and hospitalisation costs in French transplant recipients. The costs and serious adverse events of antiviral therapy for CMV prophylaxis or pre-emption add to this burden.