Rotaviruses are the single most important etiologic agents ofsevere diarrhea of infants and young children worldwide. In the present study, serological detection of rotavirus was done using an enzyme linked immunosorbent assay (ELISA), on 247 stool specimens. These were collected from children with acute diarrhea attending the outpatient clinic of Alexandria University Children's Hospital at El-Shatby, from October 2005 to April 2007. Rotavirus was detected in 33.6% of the collected samples; no specific age group or sex predilection was observed. It was presented with a marked seasonal peak during autumn and winter (58.3% and 40.5%, respectively). Rotavirus was found to be infecting most commonly under-weight children (46.9 %) resulting into fluid loss and severe dehydration (80%). Rotavirus acute gastroenteritis was found to be associated with fever (38.8%), vomiting (39.9%), watery stools, and long duration of diarrheal episodes lasting from one up to six days. The appearance of convulsions among rotavirus-positive cases even in the absence of fever (84.6%) was an important finding. Exclusive formula-fed infants appeared to exhibit the highest disease incidence (50%) while exclusive breast-fed infants had a lower incidence level (35.2%) of the disease. The virus was found to be significantly affecting children living in rural areas of Egypt (43.8%) rather than urban ones (26.1%). Environmental factors that were shown to affect the disease incidence include: the presence of impurities in water (41.6%), broken pipes (58.1%) and water tanks (58.7%) at the residence place. On the other hand, neither the kind of water source nor the presence of a sewage-disposal network was significantly related to the disease. Therefore, the study recommended to screen for rotavirus in children with diarrhea in order to avoid the use of unnecessary medications. In addition, encouragement of breast feeding practices and improvement of environmental conditions are important means of prevention of rotavirus infection.