The Authors carried out a Rotavirus investigation on the stools of 6057 children admitted in the Department of Pediatric and Pediatric Gastroenterology of Catania University, during the years 1984-1988. The stool samples of 264 children were found positive for Rotavirus. While 204 children presented gastrointestinal symptoms with diarrhoea, 12 had subclinical signs, 26 presented only respiratory symptoms and 22 had no clinical symptomatology. Moreover 122 children with diarrhoea had associated respiratory manifestations. In this study the authors punctualized that: 1) the most interested age was the first year of life; 2) there was no evidence in seasonal variations; 3) the respiratory tract was involved in high percentage of children (59.8%); 4) a transient lactase deficiency was supposed in every children with watery diarrhoea, but it was demonstrated only in 21 (10.3%).