Fifty-nine episodes of bacteremia due to Aeromonas species occurred within a 5-year period in one medical center in southern Taiwan. Underlying diseases in the 58 patients included hepatic cirrhosis (36%) and cancer (24%). Patients with aeromonas bacteremia more often had underlying hepatic cirrhosis than did those with bacteremia due to other gram-negative bacilli. Males (67%) outnumbered females. The cases appeared to cluster in the summer and fall months. Thirty-two percent were polymicrobial infections; often the Aeromonas pathogens were accompanied by other gram-negative bacilli. Aeromonas hydrophila was the most common species isolated (69%). In addition to fever, hypotension and jaundice were the common clinical manifestations of aeromonas sepsis. In cirrhotic patients, spontaneous bacterial peritonitis, altered mental status, and jaundice were most common, and aeromonas bacteremia in such patients was monomicrobial and community-acquired more often than in noncirrhotic patients. In vitro aeromonads were generally susceptible to aminoglycosides, cefuroxime, the third-generation cephalosporins, and quinolones. The overall crude fatality rate was 36%. Predictors of fatal outcome for cirrhotic patients included spontaneous bacterial peritonitis, hypotension on admission, diabetes mellitus, and high Pugh scores.