In the period of 2001-2002, a total of 1163 fecal samples were collected from children less than five years of age with diarrhea, at the Hospital Albina Patino and other health centers in Cochabamba city. Rotavirus infection general prevalence was 19%o (220), distributed among hospitalized children 24%o (77) and outpatients 17% (143). Rotavirus infections were observed along the whole study period, with highest prevalence in coldest months: April (24%), May (34%) and June (28%) and lowest frequencies (8-15%) in February, August, and September. Major rotavirus outbreak was significantly associated with the driest and colder season. The highest percentage of rotavirus infections (36,3%) was found among children between 7-12 months of age. Moderate dehydration, vomits and fever were the clinical symptoms more frequently associated with rotavirus acute gastroenteritis, being dehydration more common in hospitalized patients. The distribution of P and G genotypes analyzed by RT-PCR was: Gl (44%), G2 (6%), P[8] (24%) and P4 (15%). A co-infection P[8]P[6] was observed in 3 samples (4%). Genotype P[6] was found associated to outpatients. These findings, highlight that rotavirus is an important cause of acute gastroenteritis and that any of the currently available vaccines would potentially be protective against circulating strains found in the city of Cochabamba