Background: Diarrhea in children less than five years of age is a leading cause of morbidity and mortality. The etiology of diarrhea in more than one third of the cases is unknown. Viral agents are now the most common identifiable causes of childhood gastroenteritis. Objectives: The aims of the study were to determine the prevalence of Rotavirus, Adenovirus, Astro virus and Entero viruses in pediatric patients up to five years of age with acute gastroenteritis. Methods: An outpatient-hospital based prospective study was carried out at AL-Elweya Pediatric Hospital and Children Welfare Teaching Hospital (Baghdad) during the period from February to October 2013. Rotavirus, Adenovirus, Astrovirus and Enterovirus in fecal samples of 465 symptomatic pediatric patients with acute gastroenteritis were detected by immunochromatographic assay (ICA). Their age ranged from less than one month to 60 months with a median age of seven months. Results: Out of the 465 samples analyzed, detection of one virus- alone was found in (22.8%), (10.1), (7.3%) and (5.6%) of the diarrheal cases regarding Rota virus, Astro virus, Entero virus, and Adeno virus, respectively, yet co-infection with all four studied viral types was found in only one case (0.2%), two viruses in 65 cases (14%), and three viruses in 8 cases (1.7%). Rota- and Astro- viral diarrheas tend to occur significantly in younger- aged pediatric patients than their negative counterparts. Conclusions: A significant prevalence of gastroenteritis that associated with Rotavirus, Adenovirus, Astrovirus and Enterovirus was observed while mixed viral infections constituted a respective bulk among Iraqi pediatric patients with gastroenteritis less than five years in Baghdad.