Out of 179, diseased and dying quails of different ages examined bacteriologically, 99 birds revealed E. coli with an overall incidence reached 55. 3%. I Prevalence rate for E.coli infection detected in diseased and quails (57.8%) compared to in apparently normal ones (51.4%). O78O119O78 and O128, were the most prevalent serogroups isolated. 22.2% of E. coli isolates obtained from apparently quails were enterotoxic in baby mice only and 79.4% of E. coli serogroups isolated from diseased dying quails were enterotoxigenic. Aluminium precipitated formalized bacterins of the most prevalent E. coli serogroups were prepared. Quails of 21 old were immunized with monovalent O78 or O119 or bivalent O78 and O119 and booster dose was given one week after the first vaccination. Levels of anti-E.coli antibodies showed significant increase after the first vaccination which measured by ELISA and tube agglutination test. Protection rates reached 83.3%, 91.7% and 91.7% and 91.7% among quails immunized with monovalent O78, O119 and both O78 and O119 vaccines respectively and the results of bioassay test for testing the immunizing efficacy are described in details.