Aeromonas hydrophila was identified by culture technique in diarrhoeal stools and ascites in a patient of 57 years of age who suffered from known alcoholic cirrhosis and additional acute gastroenteritis. No other pathogens that would produce acute diarrhoea were found. The isolated Aeromonas hydrophila strain was characterised by the pathogenic properties known to date as pertaining to this species (formation of haemolysin and enterotoxins). Hence it is evident that Aeromonas hydrophila occurs in Germany also as an autochthonous pathogen of acute infectious enteritis.