Edwardsiella tarda is a Gram-negative bacterium commonly found in aquatic environments and in water-borne animals where it causes a disease named edwardsiellosis or Edwardsiella septicemia. The bacterium is distributed worldwide and has ahigh potential to infect humans, causing infections ranging from selflimited gastrointestinal disease particularly in newborns and aged, and a variety of extraintestinal infections similar to those observed in affected fish, including pyogranulomatous inflammation, abscesses and necrosis in different tissues such as the brain, liver, skin and muscles. Systemic dissemination of the micro-organism usually ends in septicemia. Many of the pathological changes induced by E. tarda in humans are consistently observed in diseased fish, and these animals seem to be an appropriate model to study the pathogenesis of edwardsiellosis. In this review we describe common and novel clinical, gross and histopathological manifestations of the entity in two commercial fish species, Japanese flounder (Paralichthys olivaceus) and tilapia hybrids (Oreochromis spp.), as well as the diversity of infections documented in humans.