A total 550 swabs were collected from balady hatcheries egg shell surface (100), infertile eggs (100), dead in shell embryos (200) and newly hatched chicks (150) for bacteriological examination. The following bacteria were isolated and identified: E.coli, Proteus spp., Pseudomonas aeruginosa, Citrobacter spp., Enterobacter spp., Staphylococcus spp. and Streptococcus spp. The most predominant isolated bacteria was E.coli (25.45%). Experimental infection for eggs were done by dipping in broth culture containing 1 × 10⁶ CFU/ml of E.coli and in 3 × 10⁸ CFU of Lactobacillus acidophilus for studying the effect of it in controlling E.coli infection and improvement of hatchability rate. The criteria used for judgment of therapeutic effect were mortality rate and rate of reisolation of E.coli from dead in shell embryos and newly hatched chicks. Dipping eggs in broth culture of Lactobacillus acidophilus then after 6 hours in broth culture of E.coli gave best results with low mortality rates and rate of reisolation than using them concurrently.