This study was carried out to evaluate the quality of drinking water in an ostrich farm through chemical and bacteriological examination. As well as isolation and identification of some pathogenic microorganisms of public health concern that is reasonably likely to be present in water. Two hundred and ten water samples were collected during summer season 2011 from an ostrich farm located at Elkassaseen, Ismailia province {main source, tanks (30 of each) and 150 from drinkers of ostrich flocks at different age}. The results were evaluated on the light of the permissible limits of WHO and/or the results obtained by other researchers, in addition to the statistical analysis of all data. The results indicated that, the highest mean values of pH, ammonia, nitrites, nitrates, phosphates, chlorides, organic matters, total hardness, total solids, Aerobic Plate Count (APC), Enterobacteriacae count, Coliform count and Staphylococcus count were recovered from drinkers water followed by those from tanks and lastly by those from the main source. On the other hand, the lowest mean values of all chemical parameters and microbial counts were recovered from drinkers water collected from ostrich flock at age 1-10 days, and then gradually increased to reach the maximum values in drinker's water of those collected at age 6-12 months. The overall occurrence % of Salmonella, E. coli and Staphylococcus aureus in all examined water samples were 5.2%, 11.9% and 8.6% respectively, and the most predominant serotypes of Salmonella was S. enteritides (4 strains), and S. typhimurium (3 strains), while the most predominant serotype of E. coli was O126:K71 (B16) (7 strains), O86:K61 (B7) (6 strains), and O55:K59 (B5) (4 strains). From the obtained results we can conclude that sites of water sampling and systems of housing and management (depending on the age of ostrich flock) are greatly affecting the water quality. Moreover, various pathogenic strains of microorganisms were isolated from water samples indicating that water may act as a dangerous source of pathogens to ostrich flock and consequently contribute to human infection with pathogens which consider a public health problem. The suggested hygienic measures to minimize water pollution were discussed.