The etiology of acute diarrhea was studied In 100 outpatient children during o 8 months period. Acute diarrhea was observed more frequently in children one to 24 months old. In total 115 pathogenic microorganisms were identified. In 48% of the patients a single pathogen was identified. 30% had a mix Infection (two or more pathogens). The frequencies for the identified microorganisms were: ECET-TE (heat stable enterotoxignic E coli) 27%. ECEP ( enteropathogenle E. coli) 28%. Rotavirus 25%. Campylobacter 10%. Salmonella 9%. ECET-TL (heat labile enterotoxigenic E. coli) 5%. Entamoeba histolytica 4%, Giarda lamblia 4%. Shigella 3%. Not Invasive microorganisms were significantly associated with a clinical course of enteritis, invasive pathogens were related to enterocolitis. The frequencies of the different pathogens found in this study do not significantly differ of reports from other tropical countries.