Diarrhea is still responsible for high rates of morbidity and mortality in children under 5 years of age. The prolongation of the acute episode may cause digestive and absorptive malfunction and, consequently, malnutrition, raising the risk of death. The objective of this review is to supply the most recent knowledge in the field of persistent diarrhea and to contribute to the decrease of its incidence. Some possible etiologic agents may be involved, including viruses, bacteria, and parasites. Treatment must be addressed to avoid malabsorption of the nutrients of the diet, associated with replacement of the hydroelectrolytic losses, to prevent its prolongation. In the great majority of the episodes, antibiotics are not indicated. Breastfeeding, introduction of safe dietary strategies to prevent protein-energy malnutrition, and improvement of sanitary conditions and hygiene are measures to be promoted with the objective of decreasing the morbidity/mortality of the diarrheic disease in children less than 5 years of age.