Three hundred sixty-three fecal specimens were collected from infants and young children with gastroenteritis over a 13-month period in Jeddah, western Saudi Arabia. Rotavirus was detected in 46% of the 363 specimens tested using an enzyme-linked immunosorbent assay (ELISA), and in 40.7% of 113 specimens using a latex agglutination test. One hundred nine of the 113 specimens that were positive by the latex agglutination test were also positive by ELISA. Electron microscopy was used to examine some specimens to demonstrate the presence of the virus. Rotavirus was detected throughout the 13-month study period, with an increase in the frequency of infection in the cooler months. Infection with this virus was more frequent among infants and children less than two-years old, with a maximum incidence among children 13–15 months old. In the 363 stool specimens tested, rotavirus was found in mixed infections with bacteria in 0.44%, with parasites in 1.31%, and with yeast in 0.66%.