Recently it has become apparent that drinking water may be a reservoir for Campylobacter and Yersinia spp. and that transmission of infection occurs by the fecal-oral route. In order to assess Campylobacter and Yersinia spp. occurrence in drinking water, 500 samples were examined for the presence of these pathogens in parallel to coliforms-fecal indicator bacteria set by E. coli. Five strains of C. jejuni (1.0%) and 20 of Yersinia spp. (4.0%) were isolated. The occurrence of C. jejuni and Yersinia spp. was statistically higher (p <.001, p <.05 respectively), in the presence of coliform bacteria. The frequency of Yersinia spp. in chlorinated and nonchlorinated samples differed significantly (p <.05), whereas C. jejuni frequency did not (p >.05).