ABSTRACTAeromonas hydrophila and other Aeromonas spp. are commonly found in fresh water and in foods. Although their isolation from stools of persons with diarrhea has implicated them as a cause of diarrheal disease, these microbes have failed to produce disease, even at very high doses, in voluntary human feeding studies. The presence of A. hydrophila in foods destined for cancer patients is certainly contraindicated, but at present Aeromonas spp. should be considered putative causes of acute gastroenteritis in normal persons. However, regulatory action based on health concerns seems insupportable at this time.