Travellers' diarrhoea remains a major public health problem, contributing to significant morbidity and disability. Because bacterial enteropathogens cause a majority of this form of diarrhoea, antibacterial drugs are effective when used in chemoprophylaxis or for empirical treatment.A review of the MEDLINE listings for travellers' diarrhoea for the past 4 years was conducted; a library of >1,000 scientific articles on the topic was also considered in developing this review. Persons who travel from industrialised countries to developing countries of the tropical and semi-tropical world are the individuals who experience travellers' diarrhoea. While diarrhoea occurs with reduced frequency among persons travelling to low-risk areas from other low- or other high-risk areas, and there remain areas of intermediate risk, this review looks primarily at the illness occurring in persons from industrialised regions visiting high-risk regions of Latin America, Africa and Southern Asia. The material reviewed deals with the high frequency of acquiring diarrhoea during international travel to high-risk areas, seen in approximately 40%, and the expected bacterial causes of illness, of which diarrhoeagenic Escherichia coli is the most important. The host risk factors associated with increased susceptibility to diarrhoea include young age, lack of previous travel to high-risk regions in the past 6 months, indiscriminate food and beverage selection patterns, and host genetics. It appears feasible to decrease the rate of illness among the travelling public by careful food and beverage selection or through chemoprophylaxis with nonabsorbed rifaximin. Chemoprophylaxis with rifaximin should help to reduce the occurrence of travellers' diarrhoea and hopefully prevent post-diarrhoea complications, including irritable bowel syndrome. Early empirical therapy with antibacterial drugs, including rifaximin, a fluoroquinolone or azithromycin, will decrease the duration of illness and return travellers more quickly to their planned activities.With collaboration between local governments and public health researchers, it may be possible to improve hygiene in areas to be visited, which may translate into reduced rates of illness. More liberal use of rifaximin prophylaxis is likely to reduce the occurrence of illness and complications of disease. Vaccines and immunoprophylactic products may be beneficial for prevention of a subset of individuals otherwise developing diarrhoea.