Travelers' diarrhea is of concern to practitioners in temperate countries in two ways: people ask advice for effective prophylaxis before they leave for tropical regions, and returning travelers often complain of diarrhea after a journey to the tropics. Diarrhea at the beginning of a trip to southern regions is mainly due to bacterial pathogens; later, a parasitic origin for diarrhea becomes an increasing possibility. A rational and economic diagnostic approach to the diarrhea of returning travelers does not necessarily and always include bacteriological stool cultures. Situations warranting a wait-and-see symptomatic treatment are discussed. The authors believe that chemoprophylaxis for traveler's diarrhea should not be prescribed as a general measure.