Plesiomonas shigelloides, a motile, oxidase-positive, Gram-negative rod that may possess shigella antigens, was isolated from the faeces of 36 children and two adults. In 13 children the organism was thought to be possibly the cause of enteritis and in eight children there was no evidence of intestinal disease. In nine children with gastroenteritis other enteropathogenic bacteria were found in addition, and six children had intestinal disease due, or possibly due, to other factors. Only four of the 38 strains had shigella antigens.