BACKGROUND: Diarrheal disease has been one of the most common health problem in Korea with Salmonella and Shigella being the major bacterial pathogens. Prevalence of enteric bacterial pathogens may differ significantly depending on the socioeconomic status of a country. Therefore, rapid improvement of living conditions in Korea should have profound effect on the incidence of enteric infection. In some Salmonella infections, proper antimicrobial treatment is important to reduce morbidity and mortality, but rapid change of the susceptibility makes the susceptibility unpredictable. So, there is a need to describe the change of antimicrobial susceptibility of Salmonella. METHODS: In this study, stool culture results at Severance Hospital during the years 1969-1998 were analyzed to determine the trends of enteric bacterial isolation and the susceptibility of the isolates. RESULTS: The proportion of S. typhi was reduced to 1.4% in 1994-1998. The proportion of Shigella was over 50% of all enteric pathogens until 1983, while only 14 strains were isolated during the last 5 years. Campylobacter spp. became the second most prevalent organism with the decrease of Shigella isolation. Ampicillin- and cotrimoxazole-susceptible nontyphoidal Salmonella gradually decreased to 76% and 90%, respectively in 1994-1998 and even several extended-spectrum beta- lactamase-producing strains were detected. Strains of ampicillin-resistant S. typhi were first detected in 1995. CONCLUSIONS: Typhoid fever and shigellosis are rare disease now in urban clinical setting while nontyphoidal Salmonella infection is a prevalent one. Campylobacter is the second most common enteric bacterial pathogen. With the increase of antimicrobial resistance of nontyphoidal Salmonella and appearance of resistant S. typhi, difficulties in the treatment of these infections may be expected in the future.