Aims: To characterize major enteric viruses (enterovirus, rotavirus, norovirus, astrovirus and adenovirus) in the sewage of Greater Cairo and to compare the results with clinical data collected during the same period. Methods and Results: Seventy-two sewage samples from two waste water treatment plants were collected from April 2006 through February 2007. Enteroviruses, noroviruses (NoVs) and rotaviruses (RVs) were detected by RT-PCR in 22%, 18% and 8 center dot 3% of the samples, respectively. No adenovirus and astrovirus was detected. G2P[8], G9P[8], G1P[8], G2P[4] and rare G12 RV isolates were detected in the environment as well as a bovine RV. The environmental NoV strains mostly belonged to genogroup I (84%). Rotaviruses and some of the NoVs were similar to those found in the clinical samples at the same time. Conclusions: The comparison of environmental and clinical data suggests that similar RV and NoV isolates were circulating in the environment and in the population during the same period. Significance and Impact of the Study: Few studies have investigated the prevalence and the epidemiology of RVs and NoVs in Cairo. This work is the first to establish a correlation between viral gastroenteritis and the concomitant presence of enteric viruses in the environment for Greater Cairo where combined environmental and clinical surveys should help to prevent infections caused by these major pathogens.