Vibrio parahaemolyticus is an extremely common organism of major importance as a cause of gastroenteritis, but not common as a cause of tissue infection. Of three patients who had serious localized tissue infections, one died because of an unnamed marine Vibrio infection. Vibrios are easily isolated, although their final speciation is quite difficult in view of their unsettled taxonomic position. It is hoped that agreement can be reached as to bacteriologic genealogy; perhaps then the specific pathogenic manifestations will be clarified. The clinician should consider the possibility of this pathogen in any patient with a wound related to saltwater or seafood. (JAMA 233:1173-1176, 1975)