A wide spectrum of disorders may cause chronic diarrhea in children and most of the times, it is not very easy to establish a specific diagnosis by pediatricians. In this review, some simple clues regarding history, physical examination, and laboratory tests are given to pediatricians in order to help their approach to the infant/child/adolescent with chronic diarrhea. Among the causes, post-enteritis syndrome, a still common but under-recognized entity especially in under-developed or developing countries, is also discussed.