The most frequent illness among persons traveling from developed to developing countries is travelers' diarrhea. Travelers to high-risk regions traditionally have been educated to exercise care in food and beverage selection. Innovative research is needed to identify ways to motivate people to exercise this care and to determine its value. Chemoprophylaxis can be recommended for certain groups while monitoring for safety, drug resistance, and efficacy against all forms of bacterial diarrhea. Research to evaluate the value of immunoprophylaxis is recommended. In the following document, the authors used an evidence base when available to determine strength and quality of evidence and when data were lacking, the panel experts provided consensus opinion.