Rotavirus testing was performed on fecal samples of 607 infants and young children aging from 0 to 6 years with acute diarrhoea between May 1986 and April 1990. Samples were analyzed by polyacrylamide gel electrophoresis (PAGE). Rotaviruses were detected in 123 samples (20.27%); from those, 107 (87.00%) were classified as subgroup II (long profile). Rotaviruses were not detected in the control group of healthy children, but it were present in 7.80% of the children hospitalized for other causes but acute diarrhoea. Most of the children with rotavirus infection ranged from 6 to 24 months of age (73.98%). The mean of positive cases during the rainy months (October to April) was of 9.60% and during the dry period was of 34.48%. The highest values were 53.17 and 73.27% in June and July, the coldest months of the year.