Shiga toxin 2f-producing Escherichia coli (O115:HNM) with eae was isolated from a symptomatic patient in Fukuoka Prefecture, Japan. The patient was a 23-year-old male and his symptoms were diarrhea, abdominal pain, headaches and a fever (37.7 degrees C). He had eaten raw chicken meat, raw chicken eggs, cooked chicken meat and raw vegetables about 13 h prior to the onset of the symptoms. The patient's specimen was examined, and no diarrheagenic agents were detected except for Shiga toxin 2f-producing E. coli (STEC(2f)) with eae. This is the first report of the serotype O115:HNM possessing stx(2f). We discuss the necessity of routinely using stx(2f)-detecting PCR primers for detection of this enteric pathogen.