Traveller's Diarrhea (TD, turista) is the most common health disturbance in travellers, affecting 20-50% of two-week travellers depending on their origin, destination and eating habits. The etiological agents most frequently isolated from the stools are enterotoxinogenic Escherichia coli (ETEC), Salmonella spp., Shigella spp., but the rate of isolation of Campylobacter spp. and non cholera vibrios is also high in Asia. Preventive measures in eating habits should in principle be able to curb the incidence of TD but compliance of travellers is usually poor. Antibiotic chemoprophylaxis has proved effective, but economic, safety and microbiological (drug resistance) considerations discourage its widespread use. Any treatment strategy should consider that TD is usually a self-limiting, benign illness in most travellers, even though infants, elderly people or persons with severe baseline diseases (heart diseases, diabetes, immunocompromised hosts, etc...) may sometimes suffer severe consequences. Adequate rehydration is the cornerstone of treatment and intestinal motility inhibitors may be used in adults (not in children) with severe diarrhea during the first 24 hours if the suspicion of invasive pathogen has been ruled out. Routine antibiotic treatment of TD is controversial, due to the benign nature of the syndrome and to the impossibility to ascertain its causative agent. It should be limited to severe and disabling cases. Among the many antibiotics tested, quinolones are now considered first-choice treatment worldwide, even though disturbing reports of the increasing prevalence of quinolone-resistant Campylobacter spp. from Asia have been recently published. Cotrimoxazole is efficient in Central America. The role of non absorbed antibiotics and probiotics is still to be fully elucidated.