Abstract: Non-cholera Vibrio infections are an important public health problem worldwide. The aim of this study was to investigate the presence of potentially pathogenic non-cholera Vibrio species in coastal seawater of Eastern Province of Saudi Arabia. A total of 300 seawater samples were collected from five locations along coast environment and examined for the presence or absence of pathogenic Vibrio species during eleven months between February and December, 2010. In this study five potentially pathogenic Vibrio species were detected, with overall incidence in the samples being at 38% for V. alginolyticus was the predominant species, 13.3 % for V. parahaemolyticus, 7.6% for V. vulnificus, 5.6% for V. cholerae non-O/non-O139 and 0.33 % for V. mimicus. All isolates of V. cholerae non-O/non-O139 were negative for cholera toxin (ctx) gene and only three isolates were positive for toxin-coregulated pilus gene (tcpA) out of 27 isolates. From the results of this study, coastal water of Arabian Gulf is concluded to be a reservoir for Vibrio species in Eastern Province of Saudi Arabia. To the best of our knowledge, this is the first study done on determining potentially pathogenic Vibrio in the Saudi Arabia and Arabian Gulf region. As the study has found that pathogenic Vibrio species are present in the study area, it is recommended that the possibility of infection caused by non cholera Vibrio should be considered whenever diagnosis is done on any patient who had recently been exposed to sea water or that had manipulated or consumed seafood and presenting infected wounds, ear infection, conjunctivitis, gastroenteritis or septic shock.