An incident of foodborne poisoning causing illness in 67 victims due to ingestion of fried fish fillets occurred in June 2011, in southern Taiwan. Of the five suspected fish fillets, one fried sample contained 62.0 mg/100 g and one raw sample contained 89.6 mg/100 g histamine, levels which are greater than the potential hazard action level (50 mg/100 g) in most illness cases. Given the allergy-like symptoms of the victims and the high histamine content in the suspected fish samples, this foodborne poisoning was strongly suspected to be caused by histamine intoxication. Five histamine-producing bacterial strains capable of producing 59 to 562 ppm of histamine in Trypticase soy broth supplemented with 1.0% L-histidine were identified as Enterobacter aerogenes (two strains), Raoultella ornithinolytica (two strains), and Morganella morganii (one strain). The degradation loss of histamine in suspected raw fillets was 28% after they were fried at 170°C for 5 min.