The data currently available on the epidemiology, severity and economic burden of nosocomial rotavirus (RV) infections in children younger than 5 years of age in the major European countries are reviewed. In most studies, RV was found to be the major etiologic agent of pediatric nosocomial diarrhea (31-87%), although the number of diarrhea cases associated with other virus infections (eg, noroviruses, astroviruses, adenoviruses) is increasing quickly and almost equals that caused by RVs. Nosocomial RV (NRV) infections are mainly associated with infants 0-5 months of age, whereas community-acquired RV disease is more prevalent in children 6-23 months of age. NRV infections are seasonal in most countries, occurring in winter; this coincides with the winter seasonal peak of other childhood virus infections (eg, respiratory syncytial virus and influenza viruses), thus placing a heavy burden on health infrastructures. A significant proportion (20-40%) of infections are asymptomatic, which contributes to the spread of the virus and might reduce the efficiency of prevention measures given as they are implemented too late. The absence of effective surveillance and of reporting of NRV infections in any of the 6 countries studied (France, Germany, Italy, Poland, Spain and the United Kingdom) results in severe underreporting of NRV cases in hospital databases and therefore in limited awareness of the importance of NRV disease at country level. The burden reported in the medical literature is potentially significant and includes temporary reduction in the quality of children's lives, increased costs associated with the additional consumption of medical resources (increased length of hospital stay) and constraints on parents'/hospital staff's professional lives. The limited robustness and comparability of studies, together with an evolving baseline caused by national changes in health care systems, do not presently allow a complete and accurate overview of NRV disease at country level to be obtained. RV is highly contagious, and the efficiency of existing prevention measures (such as handwashing, isolation and cohorting) is variable, but low at the global level because of the existence of numerous barriers to implementation (eg, lack of staff, high staff turnover, inadequate hospital infrastructure). Prevention of RV infection by mass vaccination could have a positive impact on the incidence of NRV by reducing the number of children hospitalized for gastroenteritis, therefore reducing the number of hospital cross-infections and associated costs.