A survey of bacteria in a stream receiving wastes from a textile finishing plant revealed an abnormally high number of Klebsiella in the absence of any source of fecal pollution. The density at times reached as high as 1 x 10000000 cells per milli-liter. Since this genus constitutes a part of the coliform group that is used as an index of fecal pollution and since some of its members are recognized as opportunistic pathogens, a more extensive study of randomly selected strains was carried out. Forty-nine isolates were characterized relative to their biochemical reactions, serotypes and pathogenicity for mice. All isolates conformed to the commonly accepted biochemical reaction scheme for Klebsiella. Of the strains serotyped, about one-fourth were found to be types commonly associated with human infections. Similarly, about one-fifth of the isolates examined were pathogenic for mice. These findings suggest first, that waters receiving wastes from textile finishing plants may present a false indication of human fecal pollution and second, these waters may be a reservoir of potential pathogens for those individuals predisposed to infection by Klebsiella species.