Rotavirus is the leading cause of severe diarrhoea in infants and causes an estimated 900.000 deaths annually in developing countries. In developed cauntries the rate of hospital admission for Rotavirus gastroenteritis is 3-10/1000 childrens aged less than 5 years, with an estimated 150 deaths annually in USA. Several live oral Rotavirus vaccine have been evaluated in large field trials. First generation vaccines, derived from animal strains (bovine WC3, RIT4237, Rhesus MMU18006) showed a variable protective effect with particularly low efficacy in developing countries. The vaccines derived from human attenuated strains (M37 nursery), have not been sufficientily evaluated in fields trials and do not seem to give an eterotypic protection. Polyvalent vaccines, reassorted from human and animal attenuated strains show a good protective effect (about 70%), particularly if given in three doses. It has been calculated that in USA an active vaccination programme would allow to save about 80 millions dollars/year in health expenditure and 450 millions dollars in related social costs. Rotavirus vaccination may not represent an absolute priority in comparison to other public health interventions. A cost/benefit evaluation must be made taking into account the health resources and priorities of each specific country.